Crystal and stones » diamond

Zircon as talisman

precious stones — Tue, 22 Jun 2010 23:25:26 +0000

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, [...]

Birthstone

precious stones — Fri, 18 Sep 2009 14:23:24 +0000

Birthstones have their roots in ancient astrology, and there have been many birthstone lists used over the years. The most common one today is based on a list first publicized by the U.S. jewelry industry in the 1950s.

This list assign birthstones as follows:

* January – Garnet * February – Amethyst * [...]

Topaz

precious stones — Wed, 16 Sep 2009 15:57:38 +0000

The name topaz is derived from the Greek topazos, which is the name of a small island situated in the Gulf of Arabia, from whence the Romans obtained a mineral which they called topazos and topazion, which mineral to-day is termed chrysolite.

The mineral topaz is found in Cornwall and in the British Isles [...]

Chrysoberyl

precious stones — Wed, 16 Sep 2009 15:54:00 +0000

There are certain stones and other minerals which, owing to their possession of numerous microscopically fine cavities, of a globular or tubular shape, have the appearance of “rays” or “stars,” and these are called “asteriated.”

Several of such stones have been discussed already in the last chapter, and in addition to these star-like rays, [...]

Sapphire

precious stones — Wed, 16 Sep 2009 15:48:37 +0000

The Sapphire is not so easy to imitate, as its hardness exceeds that of the ruby, and imitations containing its known constituents, or of glass, are invariably softer than the natural stone.

As before remarked, almost any form of corundum other than red is, broadly, called sapphire, but giving them their strictly correct designations, [...]

Corundum

precious stones — Wed, 16 Sep 2009 15:42:03 +0000

This mineral is a species of crystal, or crystalline alumina -an almost pure anhydrous alumina, Al2O3 -in many varieties, both of shape and colour.

The chief stone is the ruby, considered, when large, to be of even more importance and value than the diamond. There are many other red stones in this group; sapphires, [...]

Diamond

precious stones — Wed, 16 Sep 2009 15:29:11 +0000

To recapitulate certain of the facts respecting the diamond. -This wonderful gem has the distinction amongst precious stones of being unique; though many are composed of two, three, or but a small number of elements, the diamond is the only stone known consisting of one element, and absolutely nothing else -pure crystallised carbon.

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Black gemstones

precious stones — Wed, 16 Sep 2009 15:24:23 +0000

Black gemstones

Hardness. Specific Gravity.

Diamond 10 3.502-3.564 Garnet 6-1/2-7-1/2 3.400-4.500 Jet 3-1/2 1.348 Onyx (a variety of Chalcedony) 6-1/2 2.598-2.610 Quartz 7 2.670 Tourmaline (not unlike Black Resin in appearance) 7-1/4 3.024-3.300

Violet gemstones

precious stones — Wed, 16 Sep 2009 15:22:28 +0000

Violet gemstones

Hardness. Specific Gravity.

Amethyst 7 2.661 Diamond 10 3.502-3.564 Quartz (Amethyst) 7 2.670 Sapphire 9 4.049-4.060 Spinel 8 3.614-3.654 Tourmaline 7-1/4 3.160

Green gemstones

precious stones — Wed, 16 Sep 2009 15:20:47 +0000

Green gemstones

Hardness. Specific Gravity.

Aquamarine 7-3/4 2.701-2.800 Chrysoberyl 8-1/2 3.689-3.752 Chrysolite 6-7 3.316-3.528 Chrysoprase (Quartz) 7 2.670 Diamond 10 3.502-3.564 Dioptase 5 3.289 Emerald and Oriental Emerald 7-3/4 2.690 Euclase 7-1/2 3.090 Garnet (see also Red Garnet) 6-1/2-7-1/2 3.400-4.500 Heliotrope (Chalcedony) 6-1/2 2.598-2.610 Hiddenite (a variety of Spodumene) 6-1/2-7 3.130-3.200 Jade 7 [...]