Amethyst Cluster
Quartz var. Amethyst · Semi-Precious Gemstone and Mineral Specimen
Crystal System
Trigonal, prismatic crystal habit forming a cluster or druzy matrix
Mineral Group
Silicates (Tectosilicate subgroup)
Chemical Formula
SiO2 with trace iron (Fe3+) impurities
Formation Process
Hydrothermal and magmatic processes, forming in gas cavities (vesicles) within basaltic lavas where silica-rich solutions cool and crystallize at low to moderate temperatures
About This Crystal
An elongated cluster of translucent to transparent purple quartz crystals showing typical hexagonal terminations, a vitreous luster, and a lighter matrix base with visible color zoning from pale lavender to deeper purple
Physical Characteristics
Color ranges from pale lilac to deep violet; white streak; no cleavage; conchoidal fracture; specific gravity around 2.65; brittle tenacity; exhibits piezoelectricity and occasional weak green or blue fluorescence under shortwave UV
Optical Properties
Uniaxial positive with a refractive index of 1.544-1.553, birefringence of 0.009, and very faint pleochroism showing reddish-purple and bluish-purple hues
Hardness & Durability
Origin Region
Brazil, Uruguay, Madagascar, and Zambia; typically found in volcanic rock cavities or hydrothermal veins
Hardness & Durability
Mohs hardness of 7; fair to poor toughness due to lack of cleavage but susceptible to thermal shock; suitable for most jewelry with proper protective settings
Care & Maintenance
Clean with warm soapy water and a soft brush; avoid harsh chemicals, ultrasonic cleaners, and prolonged direct sunlight which can cause the purple color to fade
Rarity & Value
Common to abundant; value depends on color saturation, transparency, size, and aesthetic formation; typically affordable unless exceptionally deep-colored or flawless
Special Characteristics
Displays natural color zoning, termination faces, and crystalline druzy points on a sturdy matrix base
Lore & History
Historically used in ancient jewelry and amulets by the Greeks and Romans, who believed it prevented drunkenness; in modern metaphysical practices, it is associated with the third eye and crown chakras, inner peace, and spiritual growth