mineral
Smoky Quartz (Faceted Beads)
Silicon Dioxide (SiO2)
AI-generated identification · may be incorrectHardness: 7 on Mohs scale; Color: Brownish-grey to black (smoky); Luster: Vitreous; Crystal Structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65.
- Hardness
- 7 on Mohs scale
- Color
- Brownish-grey to black (smoky)
- Luster
- Vitreous
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Physical properties
Hardness: 7 on Mohs scale; Color: Brownish-grey to black (smoky); Luster: Vitreous; Crystal Structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65.
Formation & geological history
Formed in igneous or metamorphic rocks (especially pegmatites and hydrothermal veins) through natural irradiation of aluminum-bearing quartz over millions of years.
Uses & applications
Primarily used in jewelry, lapidary arts, and as a collector's specimen. In industry, quartz is used for its piezoelectric properties and in glass making.
Geological facts
The 'smoky' color comes from free silicon formed from the silicon dioxide by natural irradiation. It is the national gem of Scotland, where it is often called 'Cairngorm' after the mountain range.
Field identification & locations
Identify by its brownish translucent color, Mohs hardness of 7 (harder than glass), and lack of cleavage. Common in many terrains, particularly granite-rich regions like the Alps or Colorado.
