Clear Quartz
Quartz var. Rock Crystal · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Trigonal; typically prismatic with pyramidal terminations (hexagonal in appearance) and massive habits
Mineral Group
Silicates (Tectosilicate subgroup)
Chemical Formula
SiO2
Formation Process
Magmatic crystallization in pegmatites or precipitation from hydrothermal fluids in veins and geodes under various temperature and pressure conditions.
About This Crystal
Transparent to colorless crystal with a vitreous (glass-like) luster. It exhibits conchoidal fracture patterns where chipped and possesses linear growth striations on natural crystal faces.
Physical Characteristics
Color: Colorless; Streak: White; Cleavage: None (indistinct); Fracture: Conchoidal; Specific Gravity: 2.65; Fluorescence: Usually inert; Piezoelectric and pyroelectric properties.
Optical Properties
Refractive Index: 1.544–1.553; Birefringence: 0.009; Optical Character: Uniaxial positive; Dispersion: 0.013; No pleochroism.
Hardness & Durability
Origin Region
Found worldwide; notably Brazil, Arkansas (USA), Madagascar, and the Swiss Alps. Often found in hydrothermal veins and pegmatites.
Hardness & Durability
Mohs Hardness: 7; Toughness: Good (though brittle); Excellent stability and resistance to chemicals and sunlight.
Care & Maintenance
Clean with warm soapy water and a soft cloth; safe for ultrasonic and steam cleaning unless there are significant internal fractures. Store away from harder stones like Topaz or Sapphire.
Rarity & Value
Abundant and common; value depends on clarity, size, and the presence of unique inclusions. Generally affordable, with high-quality larger points demanding higher prices.
Special Characteristics
Can contain inclusions such as rutilated needles, tourmaline, chlorite, or 'phantoms' that trace earlier growth stages. Exhibits piezoelectricity when under mechanical stress.
Lore & History
Known to ancient Greeks as 'krustallos' (ice); believed to be permanently frozen water. Historically used for carving vessels and crystal balls. In modern spiritual traditions, it is considered a universal healing stone and crown chakra amplifier.