Crystal and stones » Aquamarine

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 * [...]

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, [...]

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 [...]

Phenakite to Rock-crystal

precious stones — Wed, 16 Sep 2009 14:17:44 +0000

Group E. -Stones whose specific gravity lies between 2.50 and under 3.000.

Phenakite 2.965 Turquoise 2.800 Beryl 2.709 and occasionally to 2.81 Aquamarine 2.701 ” 2.80 Labradorite 2.700 Emerald 2.690 Quartz 2.670 Chrysoprase 2.670 Jasper 2.668 Amethyst 2.661 Hornstone 2.658 Citrine 2.658 Cordierite 2.641 Agate 2.610 Chalcedony 2.598 and occasionally to 2.610 Adularia 2.567 Rock-crystal [...]