Amethyst
Quartz var. Amethyst · Semi-Precious Gemstone
Crystal System
Trigonal, with a prismatic crystal habit capped by a hexagonal pyramid
Mineral Group
Silicates (Tectosilicates)
Chemical Formula
SiO2
Formation Process
Hydrothermal and igneous processes, crystallizing from silica-rich solutions in cavities of volcanic rocks at low to moderate temperatures
About This Crystal
A polished or naturally terminated prismatic crystal point showing distinct purple color zoning, translucent to transparent clarity, and a vitreous luster
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, low birefringence of 0.009, and faint weak dichroism in reddish-violet and bluish-violet
Hardness & Durability
Origin Region
Brazil, Uruguay, Madagascar, and Zambia; typically found in volcanic geodes and hydrothermal veins
Hardness & Durability
Mohs hardness of 7, making it durable enough for everyday jewelry use though susceptible to scratching softer materials
Care & Maintenance
Clean with warm soapy water using a soft brush, avoid harsh chemicals, and store away from prolonged direct sunlight as intense UV rays can cause the purple color to fade
Rarity & Value
Common to moderately rare depending on saturation and clarity, with value driven by deep color saturation (such as Siberian grade), freedom from inclusions, and size; generally affordable for tumbled or polished points
Special Characteristics
Often exhibits color zoning (angular bands of darker and lighter purple) and occasionally phantom growth layers
Lore & History
Historically used as a gemstone in ancient Egypt and by the Greeks who believed it prevented intoxication; traditionally associated with the third eye and crown chakras, symbolizing inner peace, spiritual growth, and clarity (traditional beliefs, not scientific claims)