Smoky Quartz
Quartz var. Smoky Quartz (Silicon Dioxide) · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Trigonal; typically prismatic habits, though this specimen is polished into a sphere.
Mineral Group
Silicates (Tectosilicate)
Chemical Formula
SiO2 (with trace Al and natural irradiation)
Formation Process
Primarily magmatic in pegmatites or hydrothermal veins; smoke color results from natural radiation.
About This Crystal
A translucent to nearly opaque brownish-grey quartz sphere with a vitreous luster. Shows internal cloudy inclusions and subtle color zoning.
Physical Characteristics
Color: Smoky brown to black; Streak: White; Fracture: Conchoidal; Specific Gravity: 2.65; Fluorescence: Generally inert.
Optical Properties
Refractive Index: 1.544-1.553; Double refraction (uniaxial positive); weak pleochroism in dark specimens.
Hardness & Durability
Origin Region
Brazil, Madagascar, Switzerland (Alps), and USA (New Hampshire/Colorado).
Hardness & Durability
Mohs 7 (Hard); Great durability; no cleavage; high stability but can fade if exposed to extreme heat.
Care & Maintenance
Clean with warm soapy water; avoid prolonged exposure to direct sunlight to prevent fading; store separately from diamonds.
Rarity & Value
Common; value depends on clarity and depth of color. Very dark 'Morion' quartz is a sought-after variety.
Special Characteristics
Often contains rutile inclusions or internal 'rainbow' fractures; displays piezoelectricity when under mechanical stress.
Lore & History
Historically used in 12th-century China for sunglasses; traditionally associated with grounding and protection in crystal lore.