Smoky Quartz
Quartz var. Smoky Quartz (Silicon Dioxide) · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Trigonal; commonly occurs in hexagonal prisms with pyramid terminations, though this specimen is massive/conchoidal fragment.
Mineral Group
Silicates (Tectosilicate)
Chemical Formula
SiO2 (with trace Al and natural irradiation)
Formation Process
Igneous/Hydrothermal; crystallization from silica-rich fluids in pegmatite pockets or veins, with color resulting from natural aluminum impurities and exposure to terrestrial radiation.
About This Crystal
A translucent to transparent pale brownish-grey specimen. It displays a vitreous luster and clear conchoidal (shell-like) fracture patterns across the surface.
Physical Characteristics
Color: Pale brown/smoky; Streak: White; Cleavage: None; Fracture: Conchoidal; Specific Gravity: 2.65; Fluorescence: Usually inert.
Optical Properties
Refractive Index: 1.544–1.553; Birefringence: 0.009; Optical Character: Uniaxial positive; Weak pleochroism in darker specimens.
Hardness & Durability
Origin Region
Prominent sources include Brazil, Switzerland (the Alps), USA (Colorado), and Madagascar; formed in pegmatites and hydrothermal veins.
Hardness & Durability
Mohs Hardness: 7; Toughness: Good; Highly durable for jewelry, though susceptible to thermal shock.
Care & Maintenance
Clean with warm soapy water; avoid prolonged exposure to direct high-intensity sunlight which can fade the horizontal color in some specimens.
Rarity & Value
Common; Value is determined by clarity and color saturation. Darker 'Morion' varieties or intensely colored specimens are more valued than pale ones.
Special Characteristics
Conchoidal fracture ridges are highly visible in this specimen; may show asterism if rutile inclusions are present (not visible here).
Lore & History
Historically used in China for early sunglasses in the 12th century. Metaphysically associated with grounding, protection, and the root chakra in traditional lore.