Amethyst
Quartz var. Amethyst · Semi-Precious Gemstone
Crystal System
Trigonal, typically forming as prismatic crystals terminated by pyramids or within geodes, though this specimen is tumbled and polished into an oval shape.
Mineral Group
Silicates, specifically Tectosilicates
Chemical Formula
SiO2
Formation Process
Hydrothermal and magmatic processes, where silica-rich solutions deposit quartz in cavities within rocks at low to moderate temperatures, coupled with natural irradiation of trace iron impurities.
About This Crystal
A small, tumbled, and polished oval-shaped gemstone exhibiting a deep purple body color. It has a smooth, waxy to vitreous luster typical of polished quartz, with translucent to semi-transparent clarity and subtle internal cloudiness.
Physical Characteristics
Color is purple (varying from light lilac to deep violet); white streak; crystal cleavage is absent, breaking with a conchoidal fracture; specific gravity is approximately 2.65; brittle tenacity; exhibits piezoelectric properties.
Optical Properties
Uniaxial positive optical character with a refractive index of 1.544-1.553, low birefringence of 0.009, and weak pleochroism showing reddish-purple and bluish-purple shades.
Hardness & Durability
Origin Region
Notable sources include Brazil, Uruguay, Madagascar, Zambia, and the United States. Forms in volcanic rocks, hydrothermal veins, and pegmatites.
Hardness & Durability
Mohs hardness of 7, making it durable for general jewelry use like rings, pendants, and bracelets, with good resistance to scratching though sensitive to extreme heat.
Care & Maintenance
Clean with warm soapy water and a soft brush; avoid harsh chemicals, ultrasonic cleaners, and prolonged exposure to direct sunlight which can cause the purple color to fade.
Rarity & Value
Common to moderately rare depending on saturation and clarity; widely available and affordable, though high-grade deep purple stones from sources like Uruguay or Siberia command higher value. Treatments include heat treatment to produce citrine or green quartz.
Special Characteristics
Natural color is caused by irradiation acting on trace iron impurities incorporated into the quartz structure during growth; can exhibit color zoning.
Lore & History
Historically used as a talisman by ancient Greeks and Romans to prevent drunkenness and ensure a clear mind. In modern crystal healing, it is traditionally associated with the third eye and crown chakras, symbolizing tranquility, spiritual growth, and inner peace.