|
|
www.mineralgallery.co.za Minerals A-E |
|
|
Amethyst |
||
Name
Amethyst
Chemistry
Sio2
Uses
As a specimen and as a gemstone
Color
Purple violet to deep purple
Hardness
7
Specific gravity
2.64-2.69
Streak
White
Crystals
(Trigonal) Hexagonal prisms, pyramidal with dipyramidal ends; on prism faces almost always striated. Anomalies in development often leads to peculiarities in crystal structure such as inclusions of gas and liquid. Pseudomorphs frequent.
Accompanied by:
Feldspar, mica, calcite, tourmaline, garnet, wolframite, galena, sphaelerite, pyrite and molybdenite.
Similar to:
Beryl, fluorite, topaz, tourmaline and glass
This is one of the most popular collectors stones.
It occurs in drusses as geodes of crystals radiating inwards.
It is also found as single or doubly terminated crystals. These often have flashes of amethyst inside almost like phantoms.
They can also have smokey quarts clouds inside.
The ones from Brandberg in Namibia also have water inclusions inside. We often have some of these sought after crystals for sale in our web site.
Amethyst belongs to the quartz family. It is the purple variety. Rose Quartz is the pink variety. Citrine is the yellow variety. Smokey Quartz is the grey-black variety. Jasper is the red variety.
It is the birthstone for February.
When transparent and of good color, it is valued as a semiprecious gem and is usually step-cut or intaglio-carved. The color, thought to be caused by impurities of iron, manganese, or hydrocarbons, is changed to citrine yellow by heating the stone; most commercial citrine is heat-treated amethyst. The mineral occurs in cavities in many rock types.
The ancient Greeks attributed various powers to amethyst, notably that of protecting against drunkenness and passion, but also those of controlling evil thoughts and enhancing shrewdness. The ancients probably applied the name to purple corundum and garnet as well as to true amethyst.
