Rock Identifier
Quartz (Smoky/Clear variety) (Silicon Dioxide (SiO2)) — mineral
mineral

Quartz (Smoky/Clear variety)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Translucent grey to clear; Luster: Vitreous (glassy); Crystal Structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Hardness
7 on Mohs scale
Color
Translucent grey to clear
Luster
Vitreous (glassy)
Identified More mineral

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Physical properties

Hardness: 7 on Mohs scale; Color: Translucent grey to clear; Luster: Vitreous (glassy); Crystal Structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Formation & geological history

Formed via hydrothermal activity or cooling of silica-rich magma (igneous/pegmatitic). The coordinates (South of France/Provence) contain the Esterel Massif and Maures Massif, which are rich in metamorphic and igneous rocks where quartz is abundant.

Uses & applications

Used in electronics (piezoelectric properties), glassmaking, abrasives, and as a semi-precious gemstone in jewelry or for metaphysical collecting.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Smoky quartz gets its color from natural irradiation of aluminum impurities within the crystal lattice.

Field identification & locations

Identify in the field by its hardness (will scratch glass and steel) and lack of cleavage (breaks like glass in curved shells). It is widely found in the crystalline massifs of the Var region in France.