Amethyst
Quartz var. Amethyst · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Trigonal; hexagonal prismatic habit (this specimen is a manually carved and polished point/tower)
Mineral Group
Silicates (Tectosilicate subgroup; Quartz group)
Chemical Formula
SiO2 (Silicon Dioxide) with traces of Iron (Fe4+) and natural irradiation
Formation Process
Magmatic/Hydrothermal; forms in cavities (geodes) of volcanic rocks or in hydrothermal veins where silica-rich fluids crystallize at relatively low temperatures.
About This Crystal
Transparent to translucent purple quartz. This specific specimen is a polished hexagonal point showing distinct color zoning with concentrated purple towards the tip and base, a vitreous luster, and internal veils or 'feather' inclusions.
Physical Characteristics
Color: light to deep purple; Streak: white; Cleavage: none; Fracture: conchoidal; Specific Gravity: 2.65; Fluorescence: typically inert but may show weak bluish-green under UV.
Optical Properties
Refractive Index: 1.544-1.553; Birefringence: 0.009; Pleochroism: very weak (purple to reddish-purple); Optical Character: Uniaxial positive.
Hardness & Durability
Origin Region
Notable sources include Brazil (Rio Grande do Sul), Uruguay, Zambia, and Madagascar. Typically found in volcanic geodes or hydrothermal veins.
Hardness & Durability
Mohs Hardness: 7; Toughness: Good (no cleavage); Stable for jewelry but can fade if exposed to prolonged intense sunlight or high heat.
Care & Maintenance
Clean with warm soapy water and a soft brush; avoid ultrasonic cleaners if the stone has heavy inclusions; store away from direct sunlight to prevent color fading.
Rarity & Value
Common; value is determined by deep 'Siberian' purple color, clarity, and size. Carved points like this specimen are affordable decorative items.
Special Characteristics
Color zoning (uneven distribution of purple), internal fractures/feathers that create light reflections, and potential for weak fluorescence.
Lore & History
Historically used in Ancient Greece to prevent intoxication ('amethystos' means 'not drunken'). In lore, it is associated with the Crown Chakra and believed to promote calmness and clarity.