Amethyst

Amethyst is a gemstone from quartz family. Amethyst was and remains one of the most popular stones; it was used in many ornaments XIX - XX centuries. Russian stone was always considered as the best because at artificial light it had the reddish shade. However, amethyst can have the diversified shades from light-lavender to violet (the Siberian amethyst) in which there are the splashes of the purple colour at a cutting. The name "Siberian" is used for the description of any stone with a rich violet colour. The stone of the deep homogeneous violet colour is more expensive, than faintly-lavender.  

It is possible to find crystals of ametrine which are often amethyst, and partially - citrine, and often contain many inclusions, changing the colour. Besides, amethyst is a little dichroic, i.e. its colour has either a bluish shade, or reddish, depending on a sight corner.  

The specification

Hardness

7 on Moos scale

Density

2,65

Factor of refraction

from 1,544 to 1,553

Crystal lattice

quart forms a single crystal in the trigonal system; habitus of the crystal is 6-angles rods with 6-angles pyramidal ends. The surfaces of the crystals often have horizontal marks.

Deposits of amethyst: Russia (Urals Mountains) and the deposits are also found in Namibia and Zambia.