Amethyst is a violet colored macrocrystalline variety of quartz. It is also the most valuable of all quartz varieties. Its color can vary from light violet to deep purple. Heating amethyst gives rise to yellow and colorless tones.
At the end of the 18th century, amethyst was ranked among the most valuable gemstones and was as expensive as diamonds and rubies. Unfortunately, after the discovery of large amethyst deposits in Brazil, it was reduced to the status of a semi-precious gem.
AmethystAmethyst ring
Basic properties
Composition
SiO2
Class
Oxydes and hydroxydes
Crystal system
Trigonal
Mohs' hardness
7
Fracture
Conchoidal
Cleavage
None
Lustre
Glassy
Streak
White
Localities
Brazil, Uruguay, Mexico, Russia, Namibia, France, Morocco