Clear Quartz (Rock Crystal)
Quartz (Alpha Quartz) · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Trigonal; typically occurs as hexagonal prisms terminated by rhombohedral faces. This specimen is a massive or fractured fragment.
Mineral Group
Silicates (Tectosilicate)
Chemical Formula
SiO2
Formation Process
Primary formation occurs through hydrothermal processes in veins or as a late-stage crystallization in igneous pegmatites.
About This Crystal
A colorless, transparent to translucent mineral specimen with a vitreous (glassy) luster. Shows uneven to conchoidal fracture surfaces typical of quartz.
Physical Characteristics
Color: Colorless. Streak: White. Cleavage: Indistinct/None. Fracture: Conchoidal. Specific Gravity: 2.65. Piezoelectric and pyroelectric.
Optical Properties
Refractive Index: 1.544–1.553. Birefringence: 0.009. Uniaxial (+). No pleochroism. High transparency.
Hardness & Durability
Origin Region
Found worldwide; notable high-quality sources include Brazil (Minas Gerais), Arkansas (USA), Madagascar, and the Alps.
Hardness & Durability
Mohs Hardness: 7. Toughness: Good. Stability: High resistance to most chemicals except hydrofluoric acid.
Care & Maintenance
Excellent durability. Clean with warm soapy water. Resistant to sunlight and most household cleaners. Store away from harder stones like Topaz or Corundum.
Rarity & Value
Very common mineral. Value is driven by clarity, size, and crystal perfection. Generally inexpensive unless featuring unique inclusions.
Special Characteristics
Strongly piezoelectric; generates an electric charge under mechanical stress. May exhibit internal rainbows due to internal fractures (interference of light).
Lore & History
Historically used for carving 'crystal balls' and hardstone jewelry. In metaphysical lore, it is known as the 'Master Healer' and is associated with the Crown Chakra.