Smoky Quartz
Quartz var. Smoky Quartz (Silicon Dioxide) · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Trigonal; typically prismatic with pyramidal terminations, though this specimen is water-worn and massive/alluvial.
Mineral Group
Silicates (Tectosilicate subgroup)
Chemical Formula
SiO2 (Silicon Dioxide with trace aluminum impurities and natural irradiation)
Formation Process
Igneous/Hydrothermal: Forms from cooling magma or silica-rich hydrothermal fluids. The smoky color results from trace aluminum replacing silicon, later exposed to natural radiation.
About This Crystal
Translucent to transparent smoky brown-grey stone. It exhibits a vitreous to waxy luster with a slightly frosted, water-worn surface and internal fracturing.
Physical Characteristics
Color: Pale smoky brown; Streak: White; Cleavage: None; Fracture: Conchoidal to uneven; Specific Gravity: 2.65; Fluorescence: Generally inert.
Optical Properties
Refractive Index: 1.544–1.553; Birefringence: 0.009; Pleochroism: Weak to distinct in shades of brown; uniaxial positive.
Hardness & Durability
Origin Region
Worldwide; notable sources include Brazil, Switzerland (Alps), Colorado (USA), and Madagascar. Found in pegmatites and hydrothermal veins.
Hardness & Durability
Mohs Hardness: 7. Toughness is good due to lack of cleavage, making it highly durable for jewelry and daily handling.
Care & Maintenance
Safe to clean with warm soapy water. Avoid prolonged exposure to intense heat, which can cause color fading. Stable against most domestic chemicals.
Rarity & Value
Very common and affordable. Value is determined by transparency and color saturation; uniform 'Morion' (dark) or 'Cairngorm' (yellow-brown) varieties are prized.
Special Characteristics
Displays internal veils and fractures. When cut, it may show weak pleochroism. Naturally irradiated color is a defining feature.
Lore & History
Historically used in 12th-century China for sunglasses. Traditionally associated with grounding, protection, and the Root Chakra in metaphysical lore.