Amethyst
Quartz var. Amethyst · Semi-Precious Gemstone
Crystal System
Trigonal, with a typical prismatic crystal habit ending in a six-sided pyramid
Mineral Group
Silicates (specifically Tectosilicates)
Chemical Formula
SiO2
Formation Process
Hydrothermal and magmatic processes, forming within cavities of volcanic rocks (geodes) at low to moderate temperatures from silica-rich solutions containing trace iron.
About This Crystal
A small, rough purple crystal fragment exhibiting translucent to transparent areas with vitreous luster, characteristic of raw amethyst pieces.
Physical Characteristics
Purple body color ranging from pale lilac to deep violet, white streak, no true cleavage, conchoidal fracture, specific gravity around 2.65, brittle tenacity, and piezoelectric properties.
Optical Properties
Uniaxial positive optical character, refractive index of 1.544 to 1.553, birefringence of 0.009, generally weak dichroism displaying reddish-purple and bluish-purple hues.
Hardness & Durability
Origin Region
Brazil, Uruguay, Madagascar, Zambia, and parts of the United States. Forms predominantly in volcanic geodes and hydrothermal veins.
Hardness & Durability
Mohs hardness of 7, good durability for everyday jewelry wear, though care must be taken against sharp blows due to brittleness and lack of cleavage.
Care & Maintenance
Safe to clean with warm soapy water. Avoid prolonged direct exposure to bright sunlight to prevent fading of the purple color, and keep away from harsh hydrofluoric acid.
Rarity & Value
Common to moderately rare depending on color saturation and clarity; widely available in the gemstone and mineral market with accessible pricing for smaller specimens.
Special Characteristics
Often exhibits natural color zoning and potential minor fluid or solid inclusions.
Lore & History
Historically used by ancient Greeks and Romans to prevent intoxication. In modern metaphysical practices, it is associated with the Third Eye and Crown chakras, symbolizing peace, clarity, and spiritual growth.