Clear Quartz
Quartz var. Rock Crystal · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Trigonal; typically occurs in hexagonal prisms terminated by rhombohedrons; also massive or as druzy aggregates as seen in the specimen habit.
Mineral Group
Silicates (Tectosilicate)
Chemical Formula
SiO2
Formation Process
Primarily hydrothermal, forming from silica-rich solutions in veins and cavities; also occurs in igneous pegmatites and metamorphic rocks.
About This Crystal
Transparent to translucent icy-white appearance with a vitreous to waxy luster. This specific specimen exhibits a rough, crystalline habit with some druzy-like surface texture and uneven terminations.
Physical Characteristics
Color: Colorless to white; Streak: White; Cleavage: None (indistinct); Fracture: Conchoidal; Specific Gravity: 2.65; Fluorescence: Usually none, though some may show weak green or yellow under UV.
Optical Properties
Refractive Index: 1.544-1.553; Birefringence: 0.009 (uniaxial positive); Pleochroism: None; Dispersion: 0.013. Low dispersion with no significant optical phenomena like chatoyancy in this form.
Hardness & Durability
Origin Region
Found globally; notable sources include Brazil (Minas Gerais), USA (Arkansas), Madagascar, and the Alps.
Hardness & Durability
Mohs Hardness: 7; Toughness: Good (no cleavage planes); Stability: Very stable, resistant to most household chemicals except hydrofluoric acid.
Care & Maintenance
Clean with warm soapy water and a soft brush; ultrasonic and steam cleaners are generally safe. Store separately from softer stones to avoid scratching them.
Rarity & Value
Common; value is determined by clarity, size, and crystal perfection. Specimens with rare inclusions or unique habits command higher prices. Usually untreated.
Special Characteristics
Piezoelectric and pyroelectric properties; this specimen shows a crystalline surface that may exhibit subtle sparkle (druzy effect) under direct light.
Lore & History
Historically known as 'Krystallos' (ice) by the Greeks, who believed it was permanently frozen water. In metaphysical traditions, it is considered the 'Master Healer' and associated with the Crown Chakra.