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	<title>Crystal and stones &#187; jewel</title>
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	<description>Properties of natural crystal precious stones, birthstones, gemstones, lithotherapy, crystal healing, chakras</description>
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		<title>Zircon as talisman</title>
		<link>http://www.crystalandstones.com/talismans/zircon-as-talisman.html</link>
		<comments>http://www.crystalandstones.com/talismans/zircon-as-talisman.html#comments</comments>
		<pubDate>Tue, 22 Jun 2010 23:25:26 +0000</pubDate>
		<dc:creator>precious stones</dc:creator>
				<category><![CDATA[Talismans]]></category>
		<category><![CDATA[antidote]]></category>
		<category><![CDATA[diamond]]></category>
		<category><![CDATA[evil]]></category>
		<category><![CDATA[evil spirits]]></category>
		<category><![CDATA[Hyacinths]]></category>
		<category><![CDATA[jacinth]]></category>
		<category><![CDATA[Jargoons]]></category>
		<category><![CDATA[jewel]]></category>
		<category><![CDATA[Lyncurion]]></category>
		<category><![CDATA[Marbodus]]></category>
		<category><![CDATA[poison]]></category>
		<category><![CDATA[precious stones]]></category>
		<category><![CDATA[stone]]></category>
		<category><![CDATA[talisman]]></category>
		<category><![CDATA[virtues]]></category>
		<category><![CDATA[zircon]]></category>

		<guid isPermaLink="false">http://www.crystalandstones.com/?p=229</guid>
		<description><![CDATA[THE Zircon as talisman. The zircon includes Jacinth, or Hyacinth, and Jargoons, which, though differing in colour, are actually the same material species. As a rule amongst modern dealers in Precious Stones the White Zircon is known as the Jargoon, which is often found flawless and so bright as to closely resemble the diamond, being [...]]]></description>
			<content:encoded><![CDATA[<p>THE <a href="http://www.crystal-energy.com/advanced_search_result.php?keywords=zircon" target="_blank"><u><b>Zircon</b></u></a> as talisman. </p>
<p>The <a href="http://www.crystal-energy.com/advanced_search_result.php?keywords=zircon" target="_blank"><u><b>zircon</b></u></a> includes Jacinth, or Hyacinth, and Jargoons, which, though differing in colour, are actually the same material species. As a rule amongst modern dealers in <a href="http://www.crystalandstones.com/properties-of-precious-stones">Precious Stones</a> the White <a href="http://www.crystal-energy.com/advanced_search_result.php?keywords=zircon" target="_blank"><u><b>Zircon</b></u></a> is known as the Jargoon, which is often found flawless and so bright as to closely resemble the diamond, being in fact often offered for sale as the diamond in Indian Bazaars. </p>
<p>Jacinths, or Hyacinths, are <a href="http://www.crystal-energy.com/advanced_search_result.php?keywords=zircon" target="_blank"><u><b>Zircons</b></u></a> of deep orange or rich bright red colour, the Jacinth name being of Arabic origin, and the Hyacinth Greek, because it resembled the Hyacinth flowers which Apollo caused to spring from the blood of his favourite Hyacinthus whom he accidentally killed with a quoit. </p>
<p>The remaining varieties of this stone, which are found in varying shades of yellow, grey, brown, and green, ranging from bright lively colours to dull cloudy shades, are described generally as <a href="http://www.crystal-energy.com/advanced_search_result.php?keywords=zircon" target="_blank"><u><b>Zircons</b></u></a>, although very bright, clear, slightly coloured stones are described as pink or yellow Jargoons, according to the tint their colour may take. </p>
<p>The best specimens come from India, Ceylon, Bohemia, France, and from Australia. Boetius de Boot recommends the Oriental Jacinth, &#8220;that comes from Calicut and Cambray,&#8221; as a specific for promoting sleep ; Marbodus says it makes its wearer attractive and agreeable, which Barrett in his &#8221; Natural Magic &#8221; confirms, adding that if set in gold and worn on the finger it is a desirable jewel as a solace for a restless brain. Camillus Leonardus, writing in 1750, says the Jacinth will strengthen weak hearts, dispel imaginary suspicions, allay jealousy, secure travellers from injuries and thieves, and protect them from pestilence, plague, and contagious epidemics. </p>
<p>It was well known to the Ancients, and is considered to be the Lyncurion of Theophrastus. The popularity of this stone in India is as great as ever, and at the present time it is worn as an antidote against poison, to attract riches, honour, and wisdom, and to drive away evil spirits. </p>
<p>The virtues attributed to it during the Middle Ages were that it attracted success, brought welcome to its wearer wherever he went, stimulated the appetite, and aided digestion, protected from fever, dropsy, jaundice, and noxious fancies, and restrained from excesses, its efficacy being greatly increased if set in gold. But neither the <a href="http://www.crystal-energy.com/advanced_search_result.php?keywords=grenat" target="_blank"><u><b>Garnet</b></u></a> nor <a href="http://www.crystal-energy.com/advanced_search_result.php?keywords=zircon" target="_blank"><u><b>Zircon</b></u></a> should be worn by those whose birthdays fall in the Taurus or Scorpio periods. </p>
<div class="ngg-related-gallery"><a target="_blank" href="http://www.crystal-energy.com/advanced_search_result.php?keywords=herkimer "    title=" herkimer " class="shutterset_Related images for Zircon as talisman" ><img title="herkimer" alt="herkimer" src="http://www.crystalandstones.com/wp-content/gallery/gemstones/thumbs/thumbs_diamant-herkimer.gif" /></a>
<a target="_blank" href="http://www.crystal-energy.com/advanced_search_result.php?keywords=diamant+fume "    title=" diamant+fume " class="shutterset_Related images for Zircon as talisman" ><img title="diamant+fume" alt="diamant+fume" src="http://www.crystalandstones.com/wp-content/gallery/gemstones/thumbs/thumbs_diamant-cristal-fume.gif" /></a>
<a target="_blank" href="http://www.crystal-energy.com/advanced_search_result.php?keywords=herkimer+citrin "    title=" herkimer+citrin " class="shutterset_Related images for Zircon as talisman" ><img title="herkimer+citrin" alt="herkimer+citrin" src="http://www.crystalandstones.com/wp-content/gallery/gemstones/thumbs/thumbs_diamant-herkimer-citrine.jpg" /></a>
<a target="_blank" href="http://www.crystal-energy.com/advanced_search_result.php?keywords=pendentif+herkimer "    title=" pendentif+herkimer " class="shutterset_Related images for Zircon as talisman" ><img title="pendentif+herkimer" alt="pendentif+herkimer" src="http://www.crystalandstones.com/wp-content/gallery/gemstones/thumbs/thumbs_diamant-herkimer-pendentif.jpg" /></a>
<a target="_blank" href="http://www.crystal-energy.com/advanced_search_result.php?keywords=diamant+non+gemme "    title=" diamant+non+gemme " class="shutterset_Related images for Zircon as talisman" ><img title="diamant+non+gemme" alt="diamant+non+gemme" src="http://www.crystalandstones.com/wp-content/gallery/gemstones/thumbs/thumbs_diamant-cristal-non-gemme.gif" /></a>
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		<title>Precious stones</title>
		<link>http://www.crystalandstones.com/definition-precious-stones/precious-stones.html</link>
		<comments>http://www.crystalandstones.com/definition-precious-stones/precious-stones.html#comments</comments>
		<pubDate>Wed, 16 Sep 2009 11:09:08 +0000</pubDate>
		<dc:creator>precious stones</dc:creator>
				<category><![CDATA[Precious stones & minerals]]></category>
		<category><![CDATA[amethyst]]></category>
		<category><![CDATA[chemical]]></category>
		<category><![CDATA[colour]]></category>
		<category><![CDATA[diamonds]]></category>
		<category><![CDATA[earth]]></category>
		<category><![CDATA[facets]]></category>
		<category><![CDATA[gems]]></category>
		<category><![CDATA[gold]]></category>
		<category><![CDATA[Jerusalem]]></category>
		<category><![CDATA[jewel]]></category>
		<category><![CDATA[mineralogy]]></category>
		<category><![CDATA[minerals]]></category>
		<category><![CDATA[natural stone]]></category>
		<category><![CDATA[opal]]></category>
		<category><![CDATA[opaque]]></category>
		<category><![CDATA[precious]]></category>
		<category><![CDATA[precious stone]]></category>
		<category><![CDATA[rubies]]></category>
		<category><![CDATA[ruby]]></category>
		<category><![CDATA[silver]]></category>
		<category><![CDATA[stones]]></category>
		<category><![CDATA[turquoise]]></category>

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		<description><![CDATA[What constitutes a precious stone is the question which, at the onset, rises in the mind, and this question, simple as it seems, is one by no means easy to answer, since what may be considered precious at one time, may cease to be so at another. There are, however, certain minerals which possess distinctive [...]]]></description>
			<content:encoded><![CDATA[<p>What constitutes a precious stone is the question which, at the onset, rises in the mind, and this question, simple as it seems, is one by no means easy to answer, since what may be considered precious at one time, may cease to be so at another.</p>
<p>There are, however, certain minerals which possess distinctive features in their qualities of hardness, colour, transparency, refractability or double refractability to light-beams, which qualities place them in an entirely different class to the minerals of a metallic nature. These particular and non-metallic minerals, therefore, because of their comparative rarity, rise pre-eminently above other minerals, and become actually &#8220;precious.&#8221;</p>
<p>This is, at the same time, but a comparative term, for it will readily be understood that in the case of a sudden flooding of the market with one class of stone, even if it should be one hitherto rare and precious, there would be an equally sudden drop in the intrinsic value of the jewel to such an extent as perhaps to wipe it out of the category of <a href="http://www.crystalandstones.com/properties-of-precious-stones">precious stones</a>. For instance, rubies were discovered long before diamonds; then when diamonds were found these were considered much more valuable till their abundance made them common, and they became of little account. Rubies again asserted their position as chief of all <a href="http://www.crystalandstones.com/properties-of-precious-stones">precious stones</a> in value, and in many biblical references rubies are quoted as being the symbol of the very acme of wealth, such as in Proverbs, chapter iii., verses 13 and 15, where there are the passages, &#8220;happy is the man that findeth wisdom &#8230; she is more precious than rubies&#8221;&#8211;and this, notwithstanding the enormous quantity of them at that time obtained from the ruby mines of Ophir and Nubia, which were then the chief sources of wealth.</p>
<p>It will also be remembered that Josephus relates how, at the fall of Jerusalem, the spoil of gold was so great that Syria was inundated with it, and the value of gold there quickly dropped to one-half; other historians, also, speaking of this time, record such a glut of gold, silver, and jewels in Syria, as made them of little value, which state continued for some considerable period, till the untold wealth became ruthlessly and wastefully scattered, when the normal values slowly reasserted themselves.</p>
<p>Amongst so many varieties of these precious minerals, it cannot be otherwise than that there should be important differences in their various characteristics, though for a stone to have the slightest claim to be classed as &#8220;precious&#8221; it must conform to several at least of the following requirements:&#8211;It must withstand the action of light without deterioration of its beauty, lustre, or substance, and it must be of sufficient hardness to retain its form, purity and lustre under the actions of warmth, reasonable wear, and the dust which falls upon it during use; it must not be subject to chemical change, decomposition, disintegration, or other alteration of its substance under exposure to atmospheric air; otherwise it is useless for all practical purposes of adornment or ornamentation.</p>
<p>There are certain other characteristics of these curious minerals which may be classified briefly, thus:&#8211;Some stones owe their beauty to a wonderful play of colour or fire, due to the action of light, quite apart from the colour of the stone itself, and of this series the opal may be taken as a type. In others, this splendid play of colour is altogether absent, the colour being associated with the stone itself, in its substance, the charm lying entirely in the superb transparency, the ruby being taken as an example of this class of stone. Others, again, have not only colour, but transparency and lustre, as in the coloured diamonds, whilst the commoner well-known diamonds are extremely rich in transparency and lustre, the play of light alone showing a considerable amount of brilliancy and beauty of colour, though the stone itself is clear. Still others are opaque, or semi-opaque, or practically free from play of light and from lustre, owing their value and beauty entirely to their richness of colour.</p>
<p>In all cases the value of the stone cannot be appreciated fully till the gem is separated from its matrix and polished, and in some cases, such as in that of the diamond, cut in variously shaped facets, on and amongst which the light rays have power to play; other stones, such as the opal, turquoise and the like, are cut or ground in flat, dome-shaped, or other form, and then merely polished. It frequently happens that only a small portion of even a large stone is of supreme value or purity, the cutter often retaining as his perquisite the smaller pieces and waste. These, if too small for setting, are ground into powder and used to cut and polish other stones.</p>
<p>Broadly speaking, the greatest claim which a stone can possess in order to be classed as precious is its rarity. To this may be added public opinion, which is led for better or worse by the fashion of the moment. For if the comparatively common amethyst should chance to be made extraordinarily conspicuous by some society leader, it would at once step from its humbler position as semi-precious, and rise to the nobler classification of a truly precious stone, by reason of the demand created for it, which would, in all probability, absorb the available stock to rarity; and this despite the more entrancing beauty of the now rarer stones.</p>
<p>The study of this section of mineralogy is one of intense interest, and by understanding the nature, environment, chemical composition and the properties of the stones, possibility of fraud is altogether precluded, and there is induced in the mind&#8211;even of those with whom the study of <a href="http://www.crystalandstones.com/properties-of-precious-stones">precious stones</a> has no part commercially&#8211;an intelligent interest in the sight or association of what might otherwise excite no more than a mere glance of admiration or curiosity. There is scarcely any form of matter, be it liquid, solid, or gaseous, but has yielded or is now yielding up its secrets with more or less freedom to the scientist. By his method of synthesis (which is the scientific name for putting substances together in order to form new compounds out of their union) or of analysis (the decomposing of bodies so as to divide or separate them into substances of less complexity), particularly the latter, he slowly and surely breaks down the substances undergoing examination into their various constituents, reducing these still further till no more reduction is possible, and he arrives at their elements. From their behaviour during the many and varied processes through which they have passed he finds out, with unerring accuracy, the exact proportions of their composition, and, in many cases, the cause of their origin.</p>
<p>It may be thought that, knowing all this, it is strange that man does not himself manufacture these rare gems, such as the diamond, but so far he has only succeeded in making a few of microscopic size, altogether useless except as scientific curiosities. The manner in which these minute gems and spurious stones are manufactured, and the methods by which they may readily be distinguished from real, will be dealt with in due course.</p>
<p>The natural stones represent the slow chemical action of water, decay, and association with, or near, other chemical substances or elements, combined with the action of millions of years of time, and the unceasing enormous pressure during that time of thousands, perhaps millions, of tons of earth, rock, and the like, subjected, for a certain portion at least of that period, to extremes of heat or cold, all of which determine the nature of the gem. So that only in the earth itself, under strictly natural conditions, can these rare substances be found at all in any workable size; therefore they must be sought after assiduously, with more or less speculative risk.</p>
<div class="ngg-related-gallery"><a target="_blank" href="http://www.crystal-energy.com/advanced_search_result.php?keywords=opale "    title=" opale " class="shutterset_Related images for Precious stones" ><img title="opale" alt="opale" src="http://www.crystalandstones.com/wp-content/gallery/gemstones/thumbs/thumbs_opale_4.jpg" /></a>
<a target="_blank" href="http://www.crystal-energy.com/advanced_search_result.php?keywords=rubis "    title=" rubis " class="shutterset_Related images for Precious stones" ><img title="rubis" alt="rubis" src="http://www.crystalandstones.com/wp-content/gallery/gemstones/thumbs/thumbs_rubizoizi_0.jpg" /></a>
<a target="_blank" href="http://www.crystal-energy.com/advanced_search_result.php?keywords=amethyst "    title=" amethyst " class="shutterset_Related images for Precious stones" ><img title="amethyst" alt="amethyst" src="http://www.crystalandstones.com/wp-content/gallery/gemstones/thumbs/thumbs_amethyste_5.jpg" /></a>
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		<title>Origin of precious stones</title>
		<link>http://www.crystalandstones.com/definition-precious-stones/the-origin-of-precious-stones.html</link>
		<comments>http://www.crystalandstones.com/definition-precious-stones/the-origin-of-precious-stones.html#comments</comments>
		<pubDate>Wed, 16 Sep 2009 12:45:01 +0000</pubDate>
		<dc:creator>precious stones</dc:creator>
				<category><![CDATA[Precious stones & minerals]]></category>
		<category><![CDATA[amethyst]]></category>
		<category><![CDATA[beryl]]></category>
		<category><![CDATA[beryllium]]></category>
		<category><![CDATA[bromine]]></category>
		<category><![CDATA[calcareous]]></category>
		<category><![CDATA[carbon]]></category>
		<category><![CDATA[carbonic]]></category>
		<category><![CDATA[chemical]]></category>
		<category><![CDATA[chemistry]]></category>
		<category><![CDATA[chlorine]]></category>
		<category><![CDATA[chrysoberyl]]></category>
		<category><![CDATA[chrysolite]]></category>
		<category><![CDATA[colour]]></category>
		<category><![CDATA[crystal]]></category>
		<category><![CDATA[crystallise]]></category>
		<category><![CDATA[crystallised]]></category>
		<category><![CDATA[diamond]]></category>
		<category><![CDATA[earth]]></category>
		<category><![CDATA[earthquake]]></category>
		<category><![CDATA[emerald]]></category>
		<category><![CDATA[fluorine]]></category>
		<category><![CDATA[garnet]]></category>
		<category><![CDATA[gems]]></category>
		<category><![CDATA[geologists]]></category>
		<category><![CDATA[Glauber]]></category>
		<category><![CDATA[graphite]]></category>
		<category><![CDATA[ironstone]]></category>
		<category><![CDATA[jewel]]></category>
		<category><![CDATA[malachite]]></category>
		<category><![CDATA[metallic minerals]]></category>
		<category><![CDATA[mineralogical]]></category>
		<category><![CDATA[mineralogists]]></category>
		<category><![CDATA[minerals]]></category>
		<category><![CDATA[phosphate]]></category>
		<category><![CDATA[platinum]]></category>
		<category><![CDATA[precious stone]]></category>
		<category><![CDATA[rarer metals]]></category>
		<category><![CDATA[rock]]></category>
		<category><![CDATA[rock-crystal]]></category>
		<category><![CDATA[ruby]]></category>
		<category><![CDATA[sapphire]]></category>
		<category><![CDATA[seriatim]]></category>
		<category><![CDATA[spinel]]></category>
		<category><![CDATA[stones]]></category>
		<category><![CDATA[topaz]]></category>
		<category><![CDATA[tourmaline]]></category>
		<category><![CDATA[turquoise]]></category>
		<category><![CDATA[volcanic]]></category>
		<category><![CDATA[zircon]]></category>
		<category><![CDATA[zirconium]]></category>

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		<description><![CDATA[Though the origin, formation, composition, characteristics and tests of each stone will be examined in detail when dealing with the stones seriatim, it is necessary to enquire into those particulars of origin which are common to all, in order thoroughly to understand why they differ from other non-metallic and metallic minerals. At the very commencement [...]]]></description>
			<content:encoded><![CDATA[<p>Though the origin, formation, composition, characteristics and tests of each stone will be examined in detail when dealing with the stones seriatim, it is necessary to enquire into those particulars of origin which are common to all, in order thoroughly to understand why they differ from other non-metallic and metallic minerals.</p>
<p>At the very commencement we are faced with a subject on which mineralogists and geologists are by no means in full agreement, and there seems just ground for considerable divergence of opinion, according to the line of argument taken. It is a most remarkable fact that, precious as are certain stones, they do not (with a few exceptions) contain any of the rarer metals, such as platinum, gold, etc., or any of their compounds, but are composed entirely of the common elements and their derivatives, especially of those elements contained in the upper crust of the earth, and this notwithstanding the fact that gems are often found deep down in the earth.</p>
<p> This is very significant, and points to the conclusion that these stones were formed by the slow percolation of water from the surface through the deeper parts of the earth, carrying with it, in solution or suspension, the chemical constituents of the earth&#8217;s upper crust; time and long-continued pressure, combined with heat or cold, or perhaps both in turn, doing the rest, as already mentioned.</p>
<p>The moisture falling in dew and rain becomes acidulated with carbonic acid, CO_{2} (carbon dioxide), from the combustion and decay of organic matter, vegetation, and other sources, and this moisture is capable of dissolving certain calcareous substances, which it takes deep into the earth, till the time comes when it enters perhaps a division-plane in some rock, or some such cavity, and is unable to get away. The hollow becomes filled with water, which is slowly more and more charged with the salts brought down, till saturated; then super-saturated, so that the salts become precipitated, or perhaps crystallised out, maybe by the presence of more or other salts, or by a change in temperature. These crystals then become packed hard by further supplies and pressure, till eventually, after the lapse of ages, a natural gem is found, _exactly filling_ the cavity, and is a precious find in many cases.</p>
<p>If now we try to find its analogy in chemistry, and for a moment consider the curious behaviour of some well-known salts, under different conditions of temperature, what is taking place underground ceases to be mysterious and becomes readily intelligible.</p>
<p>Perhaps the best salt for the purpose, and one easy to obtain for experiment, is the sulphate of sodium&#8211;known also as Glauber&#8217;s Salt.</p>
<p>It is in large, colourless prisms, which may soon be dissolved in about three parts of water, so long as the water does not exceed 60Â° F., and at this temperature a super-saturated solution may easily be made. But if the water is heated the salt then becomes more and more insoluble as the temperature increases, till it is completely insoluble.</p>
<p>If a super-saturated solution of this Glauber&#8217;s Salt is made in a glass, at ordinary atmospheric temperature, and into this cold solution, without heating, is dropped a small crystal of the same salt, there will be caused a rise in temperature, and the whole will then crystallise out quite suddenly; the water will be absorbed, and the whole will solidify into a mass which exactly fits the inner contour of the vessel.</p>
<p>We have now formed what _might_ be a precious stone, and no doubt would be, if continuous pressure could be applied to it for perhaps a few thousand years; at any rate, the formation of a natural jewel is not greatly different, and after being subjected for a period, extending to ages, to the washings of moisture, the contact of its containing bed (its later matrix), the action of the changes in the temperature of the earth in its vicinity, it emerges by volcanic eruption, earthquake, landslip and the like, or is discovered as a rare and valuable specimen of some simple compound of earth-crust and water, as simple as Glauber&#8217;s Salt, or as the pure crystallized carbon.</p>
<p>It is also curious to note that in some cases the stones have not been caused by aqueous deposit in an already existing hollow, but the aqueous infusion has acted on a portion of the rock on which it rested, absorbing the rock, and, as it were, replacing it by its own substance. This is evidenced in cases where gems have been found encrusted on their matrix, which latter was being slowly transformed to the character of the jewel encrusted, or &#8220;scabbed&#8221; on it.</p>
<p>The character of the matrix is also in a great measure the cause of the variety of the stone, for it is obvious that the same salt-charged aqueous solution which undergoes change in and on ironstone would result in an entirely different product from that resting on or embedded in silica.</p>
<p>Following out the explanation of the aqueous solution, in which the earth-crust constituents are secreted, we find that the rarer and more precious metals do not generally enter into the composition of <a href="http://www.crystalandstones.com/properties-of-precious-stones">precious stones</a>&#8211;which fact may advisedly be repeated. It is, of course, to be expected that beryllium will be found in the emerald, since it is under the species beryl, and zirconium in zircon; but such instances are the exception, and we may well wonder at the actions of the infinite powers of nature, when we reflect that the rarest, costliest and most beautiful of all <a href="http://www.crystalandstones.com/properties-of-precious-stones">precious stones</a> are the simplest in their constituents.</p>
<p>Thus we find the diamond standing unique amongst all gems in being composed of one element only&#8211;carbon&#8211;being pure crystallised carbon; a different form from graphite, it is true, but, nevertheless, pure carbon and nothing else. Therefore, from its chemical, as well as from its commercial aspect, the diamond stands alone as the most important of gems.</p>
<p>The next in simplicity, whilst being the most costly of all, is the ruby, and with this may be classed the blue sapphire, seeing that their chemical constituents are exactly the same, the difference being one of colour only. These have two elements, oxygen and aluminium, which important constituents appear also in other stones, but this example is sufficient to prove their simplicity of origin.</p>
<p>Another unique stone is the turquoise, in that it is the only rare gem essentially containing a great proportion of water, which renders it easily liable to destruction, as we shall see later. It is a combination of alumina, water, and phosphoric acid, and is also unique in being the only known valuable stone containing a phosphate.</p>
<p>Turning to the silica series, we again find a number of gems with two elements only, silica&#8211;an important constituent of the earth&#8217;s crust&#8211;and oxygen&#8211;an important constituent of atmospheric air. In this group may be mentioned the opal, amethyst, agate, rock-crystal, and the like, as the best known examples, whilst oxygen appears also mostly in the form of oxides, in chrysoberyl, spinel, and the like. This silica group is extremely interesting, for in it, with the exception of the tourmaline and a few others, the composition of the gems is very simple, and we find in this group such stones as the chrysolite, several varieties of topaz, the garnet, emerald, etc., etc.</p>
<p>Malachite and similar stones are more ornamental than precious, though they come in the category of <a href="http://www.crystalandstones.com/properties-of-precious-stones">precious stones</a>. These are the carbonate series, containing much carbonic acid, and, as may be expected, a considerable proportion of water in their composition, which water can, of course, be dispelled by the application of heat, but to the destruction of the stone.</p>
<p>From all this will be seen how strong is the theory of aqueous percolation, for, given time and pressure, water charged with earth-crust constituents appears to be the origin of the formation of all <a href="http://www.crystalandstones.com/properties-of-precious-stones">precious stones</a>; and all the <a href="http://www.crystalandstones.com/properties-of-precious-stones">precious stones</a> known have, when analysed, been found to be almost exclusively composed of upper-earth-crust constituents; the other compounds which certain stones contain may, in all cases, be traced to their matrix, or to their geological or mineralogical situation.</p>
<p>In contradistinction to this, the essentially underground liquids, with time and pressure, form metallic minerals and mineralise the rocks, instead of forming gems.</p>
<p>Thus we see that in a different class of minerals&#8211;compounds of metals with the sulphates, such as sulphuric acid and compounds; also those containing the metallic sulphides; in cases where the metalliferous ores or the metallic elements enter into composition with the halogens&#8211;bromine, chlorine, fluorine, and iodine&#8211;in all these, <a href="http://www.crystalandstones.com/properties-of-precious-stones">precious stones</a> are comparatively common, but the stones of these groups are invariably those used for decorative or ornamental purposes, and true &#8220;gems&#8221; are entirely absent.</p>
<p>It would therefore appear that though metallic minerals, as already mentioned, are formed by the action of essentially _underground_ chemically-charged water&#8211;combined with ages of time and long-continued pressure, rocks and earth being transformed into metalliferous ores by the same means&#8211;<a href="http://www.crystalandstones.com/properties-of-precious-stones">precious stones</a> (or that portion of them ranking as jewels or gems) must on the contrary be wholly, or almost wholly, composed of _upper_-earth-crust materials, carried deep down by water, and subjected to the action of the same time and pressure; the simpler the compound, the more perfect and important the result, as seen in the diamond, the ruby, and the like.</p>
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		<title>Hardness of gems and jewels</title>
		<link>http://www.crystalandstones.com/physical-properties/hardness.html</link>
		<comments>http://www.crystalandstones.com/physical-properties/hardness.html#comments</comments>
		<pubDate>Wed, 16 Sep 2009 13:47:09 +0000</pubDate>
		<dc:creator>precious stones</dc:creator>
				<category><![CDATA[Classification of gems]]></category>
		<category><![CDATA[Apatite]]></category>
		<category><![CDATA[beauty]]></category>
		<category><![CDATA[calcite]]></category>
		<category><![CDATA[classification]]></category>
		<category><![CDATA[cleavage]]></category>
		<category><![CDATA[colour]]></category>
		<category><![CDATA[corundum]]></category>
		<category><![CDATA[cut gem]]></category>
		<category><![CDATA[diamond]]></category>
		<category><![CDATA[Felspar]]></category>
		<category><![CDATA[Fluorspar]]></category>
		<category><![CDATA[gem]]></category>
		<category><![CDATA[girdle]]></category>
		<category><![CDATA[Gypsum]]></category>
		<category><![CDATA[Hardness]]></category>
		<category><![CDATA[iron]]></category>
		<category><![CDATA[jewel]]></category>
		<category><![CDATA[manganese]]></category>
		<category><![CDATA[mineral]]></category>
		<category><![CDATA[Mohs]]></category>
		<category><![CDATA[Mohs table]]></category>
		<category><![CDATA[powder]]></category>
		<category><![CDATA[precious]]></category>
		<category><![CDATA[Precious stones & minerals]]></category>
		<category><![CDATA[quartz]]></category>
		<category><![CDATA[rarity]]></category>
		<category><![CDATA[rock-crystal]]></category>
		<category><![CDATA[Rock-salt]]></category>
		<category><![CDATA[ruby]]></category>
		<category><![CDATA[steel]]></category>
		<category><![CDATA[stone]]></category>
		<category><![CDATA[talc]]></category>
		<category><![CDATA[topaz]]></category>

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		<description><![CDATA[Hardness is perhaps one of the most important features in a stone, especially those of the &#8220;gem&#8221; series, for no matter how colour, lustre, general beauty and even rarity may entitle a stone to the designation &#8220;precious,&#8221; unless it possesses great hardness it cannot be used as a gem or jewel. Consequently, the hardness of [...]]]></description>
			<content:encoded><![CDATA[<p>Hardness is perhaps one of the most important features in a stone, especially those of the &#8220;gem&#8221; series, for no matter how colour, lustre, general beauty and even rarity may entitle a stone to the designation &#8220;precious,&#8221; unless it possesses great hardness it cannot be used as a gem or jewel.</p>
<p>Consequently, the hardness of jewels is a matter of no small importance, and by dint of indefatigable research, in tests and comparison, all known <a href="http://www.crystalandstones.com/properties-of-precious-stones">precious stones</a> have been classified in various scales or degrees of hardness. </p>
<p>The most popular and reliable table is that of Mohs, in which he takes talc as the softest of the rarer minerals and classes this as No. 1; from that he goes by gradual steps to the diamond, the hardest of the stones, which he calls No. 10, and between these two all other gems are placed. Here is given a complete list of Mohs&#8217;s arrangement of stones, according to their hardness, beginning at No. 1, thus:</p>
<p> <UL>
<ol>
<li>Talc</li>
<li>Rock-salt  or Gypsum</li>
<li>Calcite</li>
<li>Fluorspar</li>
<li>Apatite</li>
<li>Felspar</li>
<li>Quartz</li>
<li>Topaz</li>
<li>Corundum</li>
<li>Diamond</li>
</ol>
</ul>
<p>The stone under examination may perhaps first be somewhat roughly classified by its colour, cleavage, and general shape. One of these standard stones is then gently rubbed across its surface and then others of increasingly higher degrees, till no scratch is evident under a magnifying glass. Thus if quartz ceases to scratch it, but a topaz will do so, the degree of hardness must lie between 7 and 8. </p>
<p>Then we reverse the process: the stone is passed over the standard, and if both quartz and topaz are scratched, then the stone is at least equal in hardness to the topaz, and its classification becomes an easy matter.</p>
<p>Instead of stones, some experts use variously-tempered needles of different qualities and compositions of iron and steel. For instance, a finely-tempered ordinary steel needle will cut up to No. 6 stones; one made of tool steel, up to 7; one of manganese steel, to 7-1/2; one made of high-speed tool steel, to 8 and 8-1/2, and so on, according to temper; so that from the scratch which can be made with the finger-nail on mica, to the hardness of the diamond, which diamond alone will scratch readily, the stones may be picked out, classified and tested, with unerring accuracy.</p>
<p>It will thus be seen how impossible it is, even in this one of many tests, for an expert to be deceived in the purchase of <a href="http://www.crystalandstones.com/properties-of-precious-stones">precious stones</a>, except through gross carelessness&#8211;a fault seldom, if ever, met with in the trade. For example&#8211;a piece of rock-crystal, chemically coloured, and cut to represent a ruby, might appear so like one as to deceive a novice, but the mere application to its surface of a real ruby, which is hardness 9, or a No. 9 needle, would reveal too deep or powdery a scratch; also its possibility of being scratched by a topaz or a No. 8 needle, would alone prove it false, for the corundum group, being harder than No. 8, could not be scratched by it. </p>
<p>So would the expert go down the scale, the tiny scratches becoming fainter as he descended, because he would be approaching more nearly the hardness of the stone under test, till he arrived at the felspar, No. 6, which would be too soft to scratch it, yet the stone would scratch the felspar, but not zircon or andalusite, 7-1/2, or topaz, 8, so that his tests would at once classify the stone as a piece of cut and coloured quartz, thus confirming what he would, at the first sight, have suspected it to be.</p>
<p>The standard stones themselves are much more certain in results than the needles, which latter, though well selected and tempered, are not altogether reliable, especially in the more delicate distinctions of picking out the hardest of certain stones of the same kind, in which cases only the expert judge can decide with exactness. Accurate in this the expert always is, for he judges by the sound and depth of his cut, and by the amount and quality of the powder, often calling the microscope to his aid, so that when the decision is made finally, there is never the least doubt about it.</p>
<p>Rapidly as these tests can be made, they are extremely reliable, and should the stone be of great value, it is also subjected to other unerring tests of extreme severity, any one of which would prove it false, if it chanced to be so, though some stones are manufactured and coloured so cleverly that to all but the expert judge and experienced dealer, they would pass well for the genuine.</p>
<p>In Mohs&#8217;s list it will be seen that several stones vary considerably, the opal, for instance, having a degree of hardness from 5-1/2 to 6-1/2 inclusive. All stones differ slightly, though almost all may be said to fit their position in the scale; but in the case of the opal, the difference shown is partly due to the many varieties of the stone, as described in the last chapter.</p>
<p>In applying this test of hardness to a cut gem, it will be noticed that some parts of the same stone seem to scratch more readily than others, such as on a facet at the side, which is often softer than those nearest the widest part of the stone, where the claws, which hold it in its setting, usually come. </p>
<p>This portion is called the &#8220;girdle,&#8221; and it is on these &#8220;girdle&#8221; facets that the scratches are generally made. This variation in hardness is mostly caused by cleavage, these cleavage planes showing a marked, though often but slight, difference in the scratch, which difference is _felt_ rather than seen. In addition to the peculiar _feel_ of a cutting scratch, is the _sound_ of it. </p>
<p>On a soft stone being cut by a hard one, little or no sound is heard, but there will form a plentiful supply of powder, which, on being brushed off, reveals a more or less deep incision. But as the stones approach one another in hardness, there will be little powder and a considerable increase in the noise; for the harder are the stones, cutting and being cut, the louder will be the sound and the less the powder. An example of this difference is evident in the cutting of ordinary glass with a &#8220;set&#8221; or &#8220;glazier&#8217;s&#8221; diamond, and with a nail. </p>
<p>If the diamond is held properly, there will be heard a curious sound like a keen, drawn-out &#8220;kiss,&#8221; the diamond being considerably harder than the material it cut. An altogether different sound is that produced by the scratching of glass with a nail. In this case, the relative difference in hardness between the two is small, so that the glass can only be scratched and not &#8220;cut&#8221; by the nail; it is too hard for that, so the noise is much greater and becomes a screech. </p>
<p>Experience, therefore, makes it possible to tell to a trifle, at the first contact, of what the stone is composed, and in which class it should be placed, by the mere &#8220;feel&#8221; of the scratch, the depth of it, the amount and kind of powder it leaves, and above all, by the sound made, which, even in the tiniest scratch, is quite characteristic.</p>
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		<title>Cutting of precious stones</title>
		<link>http://www.crystalandstones.com/cutting-stones/cutting-of-precious-stones.html</link>
		<comments>http://www.crystalandstones.com/cutting-stones/cutting-of-precious-stones.html#comments</comments>
		<pubDate>Wed, 16 Sep 2009 14:43:37 +0000</pubDate>
		<dc:creator>precious stones</dc:creator>
				<category><![CDATA[Cut and polished gemstones]]></category>
		<category><![CDATA[cabochon]]></category>
		<category><![CDATA[carats]]></category>
		<category><![CDATA[carbuncle]]></category>
		<category><![CDATA[cat's-eye]]></category>
		<category><![CDATA[colour]]></category>
		<category><![CDATA[coloured stones]]></category>
		<category><![CDATA[crown]]></category>
		<category><![CDATA[Cullinan]]></category>
		<category><![CDATA[cutting]]></category>
		<category><![CDATA[diamond]]></category>
		<category><![CDATA[facet]]></category>
		<category><![CDATA[garnet]]></category>
		<category><![CDATA[goutte de suif]]></category>
		<category><![CDATA[Great Mogul]]></category>
		<category><![CDATA[jewel]]></category>
		<category><![CDATA[Koh-i-nur]]></category>
		<category><![CDATA[moonstone]]></category>
		<category><![CDATA[opaque]]></category>
		<category><![CDATA[polishing]]></category>
		<category><![CDATA[Precious stones & minerals]]></category>
		<category><![CDATA[purity]]></category>
		<category><![CDATA[rare]]></category>
		<category><![CDATA[Stars of Africa]]></category>
		<category><![CDATA[table cut]]></category>
		<category><![CDATA[tallow-drop]]></category>
		<category><![CDATA[trap]]></category>
		<category><![CDATA[value]]></category>

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		<description><![CDATA[As existing in a state of nature precious stones do not, as a rule, exhibit any of those beautiful and wonderful properties which cause them to be so admired and sought after as to become of great intrinsic value, for their surfaces have become clouded by innumerable fine cuts or abrasions, because of the thousands [...]]]></description>
			<content:encoded><![CDATA[<p>As existing in a state of nature <a href="http://www.crystalandstones.com/properties-of-precious-stones">precious stones</a> do not, as a rule, exhibit any of those beautiful and wonderful properties which cause them to be so admired and sought after as to become of great intrinsic value, for their surfaces have become clouded by innumerable fine cuts or abrasions, because of the thousands of years during which they have been under pressure, or tumbled about in rivers, or subjected to the incessant friction caused by surrounding substances. </p>
<p>All this occurring above and under ground has given them an appearance altogether different to that which follows cutting and polishing. Further, the shape of the stone becomes altered by the same means, and just as Michael Angelo&#8217;s figure was already in the marble, as he facetiously said, and all he had to do was to chip off what he did not require till he came to it, so is the same process of cutting and polishing necessary to give to the <a href="http://www.crystalandstones.com/properties-of-precious-stones">precious stones</a> their full value, and it is the manner in which these delicate and difficult operations are performed that is now under consideration. </p>
<p>Just as experience and skill are essential to the obtaining of a perfect figure from the block of marble, so must the cutting and polishing of a precious stone call for the greatest dexterity of which a workman is capable, experience and  skill so great as to be found only in the expert, for in stones of great value even a slight mistake in the shaping and cutting would probably not only be wasteful of the precious material, but would utterly spoil its beauty, causing incalculable loss, and destroying altogether the refrangibility, lustre and colour of the stone, thus rendering it liable to easy fracture: in every sense converting what would have been a rare and magnificent jewel to a comparatively valueless specimen.</p>
<p>One of the chief services rendered by <a href="http://www.crystalandstones.com/properties-of-precious-stones">precious stones</a> is that they may be employed as objects of adornment, therefore, the stone must be cut of such a shape as will allow of its being set without falling out of its fastening -not too shallow or thin, to make it unserviceable and liable to fracture, and in the case of a transparent stone, not too deep for the light to penetrate, or much colour and beauty will be lost. </p>
<p>Again, very few stones are flawless, and the position in which the flaw or flaws appear will, to a great extent, regulate the shape of the stones, for there are some positions in which a slight flaw would be of small detriment, because they would take little or no reflection, whilst in others, where the reflections go back and forth from facet to facet throughout the stone, a flaw would be magnified times without number, and the value of the stone greatly reduced. </p>
<p>It is therefore essential that a flaw should be removed whenever possible, but, when this is not practicable, the expert will cut the stone into such a shape as will bring the defect into the least important part of the finished gem, or probably sacrifice the size and weight of the original stone by cutting it in two or more pieces of such a shape that the cutting and polishing will obliterate the defective portions. Such a method was adopted with the great Cullinan diamond. From this remarkable diamond a great number of magnificent stones were obtained, the two chief being the largest and heaviest at present known. Some idea of the size of the original stone may be gathered from the fact that the traditional Indian diamond, the &#8220;Great Mogul,&#8221; is said to have weighed 280 carats. </p>
<p>This stone, however, is lost, and some experts believe that it was divided, part of it forming the present famous Koh-i-nur; at any rate, all trace of the Great Mogul ceased with the looting of Delhi in 1739. The Koh-i-nur weighs a little over 106 carats; before cutting it weighed a shade over 186; the Cullinan, in the same state, weighed nearly 3254 carats. </p>
<p>This massive diamond was cut into about 200 stones, the largest, now placed in &#8220;The Royal Sceptre with the Cross,&#8221; weighing 516-1/2 carats, the second, now placed under the historic ruby in &#8220;The Imperial State Crown,&#8221; weighing 309-3/16ths carats. These two diamonds are now called &#8220;The Stars of Africa.&#8221; </p>
<p>Both these stones, but especially the larger, completely overshadow the notorious Koh-i-nur, and notwithstanding the flaw which appeared in the original stone, every one of the resulting pieces, irrespective of weight, is without the slightest blemish and of the finest colour ever known, for the great South African diamond is of a quality never even approached by any existing stone, being ideally perfect.</p>
<p>It requires a somewhat elaborate explanation to make clear the various styles of cut without illustrations. They are usually divided into two groups, with curved,  and with flat or plane surfaces. Of the first, the curved surfaces, opaque and translucent stones, such as the moonstone, cat&#8217;s-eye, etc., are mostly cut en cabochon, that is, dome-shaped or semi-circular at the top, flat on the underside, and when the garnet is so cut it is called a carbuncle. </p>
<p>In strongly coloured stones, while the upper surface is semi-circular like the cabochon, the under surface is more or less deeply concave, sometimes following the curve of the upper surface, the thickness of the stone being in that case almost parallel throughout. </p>
<p>This is called the &#8220;hollow&#8221; cabochon. Other stones are cut so that the upper surface is dome-shaped like the last two, but the lower is more or less convex, though not so deep as to make the stone spherical. This is called the &#8220;double&#8221; cabochon.</p>
<p>A further variety of cutting is known as the goutte de suif, or the &#8220;tallow-drop,&#8221; which takes the form of a somewhat flattened or long-focus double-convex lens. The more complicated varieties of cut are those appearing in the second group, or those with plane surfaces. </p>
<p>A very old form is the &#8220;rose&#8221; or &#8220;rosette&#8221;; in this the extreme upper centre, called the &#8220;crown,&#8221; or &#8220;star,&#8221; is usually composed of six triangles, the apexes of which are elevated and joined together, forming one point in the centre. From their bases descend a further series of triangles, the bases and apexes of which are formed by the bases and lower angles of the upper series. This lower belt is called the &#8220;teeth,&#8221; under which the surface or base of the stone is usually flat, but sometimes partakes of a similar shape to the upper surface, though somewhat modified in form. </p>
<p>Another variety is called the &#8220;table cut,&#8221; and is used for coloured stones. It has a flat top or &#8220;table&#8221; of a square or other shape, the edges of which slope outwards and form the &#8220;bezils&#8221; or that extended portion by which the stone is held in its setting. It will thus be seen that the outside of the stone is of the same shape as that of the &#8220;table,&#8221; but larger, so that from every portion of the &#8220;table&#8221; the surface extends downwards, sloping outwards to the extreme size of the stone, the underside sloping downwards and inwards to a small and flat base, the whole, in section, being not unlike the section of a &#8220;pegtop.&#8221;</p>
<p>A modification of this is known as the &#8220;step&#8221; cut, sometimes also called the &#8220;trap.&#8221; Briefly, the difference between this and the last is that whereas the table has usually one bevel on the upper and lower surfaces, the trap has one or more steps in the sloping parts, hence its name.</p>
<p>The most common of all, and usually applied only to the diamond, is the &#8220;brilliant&#8221; cut. This is somewhat complicated, and requires detailed description. In section, the shape is substantially that of a pegtop with a flat &#8220;table&#8221; top and a small flat base. The widest portion is that on which the claws, or other form of setting, hold it securely in position. This portion is called the &#8220;girdle,&#8221; and if we take this as a defining line, that portion which appears above the setting of this girdle, is called the &#8220;crown&#8221;; the portion below the girdle is called the &#8220;culasse,&#8221; or less commonly the &#8220;pavilion.&#8221; </p>
<p>Commencing with the girdle upwards, we have eight &#8220;cross facets&#8221; in four pairs, a pair on each  side; each pair having their apexes together, meeting on the four extremities of two lines drawn laterally at right angles through the stone. It will, therefore, be seen that one side of each triangle coincides with the girdle, and as their bases do not meet, these spaces are occupied by eight small triangles, called &#8220;skill facets,&#8221; each of which has, as its base, the girdle, and the outer of its sides coincides with the base of the adjoining &#8220;cross facet.&#8221; </p>
<p>The two inner sides of each pair of skill facets form the half of a diamond or lozenge-shaped facet, called a &#8220;quoin,&#8221; of which there are four. The inner or upper half of each of these four quoins forms the bases of two triangles, one at each side, making eight in all, which are called &#8220;star facets,&#8221; and the inner lines of these eight star facets form the boundary of the top of the stone, called the &#8220;table.&#8221; The inner lines also of the star facets immediately below the table and those of the cross facets immediately above the girdle form four &#8220;templets,&#8221; or &#8220;bezils.&#8221; We thus have above the girdle, thirty-three facets: 8 cross, 8 skill, 4 quoin, 8 star, 1 table, and 4 templets.</p>
<p>Reversing the stone and again commencing at the girdle, we have eight &#8220;skill facets,&#8221; sometimes called the lower skill facets, the bases of which are on the girdle, their outer sides forming the bases of eight cross facets, the apexes of which meet on the extremities of the horizontal line, as in those above the girdle. If the basal lines of these cross facets, where they join the sides of the skill facets, are extended to the peak, or narrow end of the stone, these lines, together with the sides of the cross facets, will form four five-sided facets, called the &#8220;pavilions&#8221;; the spaces between these four pavilions have their ends nearest the girdle formed by the inner sides of the skill facets, and of these spaces, there will, of course, be four, which also are five-sided figures, and are called &#8220;quoins,&#8221; so that there are eight five-sided facets -four large and four narrow -their bases forming a square, with a small portion of each corner cut away; the bases of the broader pavilions form the four sides, whilst the bases of the four narrower quoins cut off the corners of the square, and this flat portion, bounded by the eight bases, is called the &#8220;culet,&#8221; but more commonly &#8220;collet.&#8221; So that below the girdle, we find twenty-five facets: 8 cross, 8 skill, 4 pavilion, 4 quoin, and 1 collet.</p>
<p>These, with the 33 of the crown, make 58, which is the usual number of facets in a brilliant, though this varies with the character, quality, and size of the diamond. For instance, though this number is considered the best for normal stones, specially large ones often have more, otherwise there is danger of their appearing dull, and it requires a vast amount of skill and experience to decide upon the particular number and size of the facets that will best display the fire and brilliance of a large stone, for it is obvious that if, after months of cutting and polishing, it is found that a greater or smaller number of facets ought to have been allowed, the error cannot be retrieved without considerable loss, and probable ruin to the stone. </p>
<p>In the case of the Cullinan diamonds, the two largest of which are called the Stars of Africa, 74 facets were cut in the largest portion, while in the next largest the experts  decided to make 66, and, as already pointed out, these stones are, up to the present time, the most magnificent in fire, beauty and purity ever discovered.</p>
<p>The positions and angles of the facets, as well as the number, are of supreme importance, and diamond cutters -even though they have rules regulating these matters, according to the weight and size of the stone -must exercise the greatest care and exactitude, for their decision once made is practically unalterable.</p>
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