Clear Quartz
Quartz (Variety: Rock Crystal) · Semi-Precious Gemstone and Mineral Specimen
Crystal System
Trigonal crystal system, typically forming prismatic crystals terminated by six-sided pyramids in its natural unpolished state.
Mineral Group
Silicates (specifically Tectosilicates)
Chemical Formula
SiO2
Formation Process
Forms primarily through hydrothermal solutions, pegmatitic pockets, and igneous crystallization under high temperatures and pressures.
About This Crystal
A small, tumbled, smooth specimen of colorless quartz, displaying translucent to transparent clarity with a vitreous to waxy luster.
Physical Characteristics
Colorless body color with a white streak. It exhibits a conchoidal fracture, lacks distinct cleavage, and has a specific gravity of approximately 2.65.
Optical Properties
Uniaxial positive optical character with a refractive index of 1.544 to 1.553 and strong birefringence. It is doubly refractive.
Hardness & Durability
Origin Region
Found globally with notable commercial deposits in Brazil, Madagascar, the United States (Arkansas), and the Alps.
Hardness & Durability
Mohs hardness of 7, making it durable for daily wear. It has good toughness and no true cleavage planes.
Care & Maintenance
Clean with warm soapy water and a soft brush. Avoid harsh chemicals and sudden thermal shock, though it is generally stable in light.
Rarity & Value
Very common and widely available. Tumbled stones of this quality are inexpensive and widely accessible.
Special Characteristics
Exhibits piezoelectric and pyroelectric properties. Can sometimes contain fluid inclusions or internal fractures creating slight rainbow refractions.
Lore & History
Historically regarded by ancient civilizations such as the Romans and Indigenous groups as frozen water or a powerful spiritual tool for clarity and amplification.