Amethyst Cluster
Quartz var. Amethyst · Semi-Precious Gemstone and Mineral Specimen
Crystal System
Trigonal, with a microcrystalline to macrocrystalline habit forming prismatic quartz crystals terminating in points, commonly found as geodes or druzy clusters.
Mineral Group
Silicates (specifically Tectosilicates)
Chemical Formula
SiO2
Formation Process
Hydrothermal and magmatic processes, where silica-rich fluids cool and precipitate quartz crystals within cavities of volcanic basalt at low to moderate temperatures.
About This Crystal
The specimen held in the hand displays a cluster of light purple to pale violet quartz crystals, featuring translucent to semi-translucent properties with a vitreous luster. It exhibits natural zoning and a characteristic druzy crystal face texture on the surface.
Physical Characteristics
Color ranges from pale lilac to deep purple; white streak; no true cleavage with a conchoidal fracture; specific gravity around 2.65; brittle tenacity; displays piezoelectric and pyroelectric properties; typically non-fluorescent though some specimens show weak green or blue under UV.
Optical Properties
Singly or doubly refractive depending on the perspective, specifically uniaxial positive with a refractive index of 1.544 to 1.553, low birefringence of 0.009, and faint dichroism in shades of purple/reddish-purple.
Hardness & Durability
Origin Region
Notable sources include Brazil, Uruguay, Madagascar, Zambia, and the United States (such as Arizona and Arkansas). Typically forms in volcanic rock cavities or hydrothermal veins.
Hardness & Durability
Mohs hardness of 7, making it durable enough for everyday jewelry wear, though care must be taken against sharp impacts due to brittleness.
Care & Maintenance
Clean with warm soapy water using a soft brush. Avoid harsh chemical cleaners, ultrasonic cleaners if fractures are present, and prolonged exposure to direct sunlight which can cause the purple color to fade.
Rarity & Value
Common to uncommon depending on color saturation and clarity; large or deeply saturated clusters command higher values. Heat treatment to yellow (citrine) or green (prasiolite) is sometimes applied.
Special Characteristics
May feature phantom inclusions, color zoning, or slight fluid inclusions within the quartz matrix, along with piezoelectric properties.
Lore & History
Historically revered by ancient Greeks and Romans as a preventive against drunkenness and to keep the wearer clear-headed. In modern metaphysical practices, it is associated with the third eye and crown chakras, symbolizing peace, spiritual growth, and clarity.