mineral

Quartz (Smoky Quartz variant)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale. Color: Grayish-brown, translucent to transparent. Luster: Vitreous. Crystal Structure: Hexagonal (trigonal). Cleavage: None (conchoidal fracture). Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Grayish-brown, translucent to transparent
Luster: Vitreous

Identified June 16, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale. Color: Grayish-brown, translucent to transparent. Luster: Vitreous. Crystal Structure: Hexagonal (trigonal). Cleavage: None (conchoidal fracture). Specific Gravity: 2.65.

Formation & geological history

Formed from the crystallization of silica-rich magma in igneous rocks like granite, or precipitated from hydrothermal fluids. The smoky color is a result of natural irradiation of trace aluminum impurities.

Uses & applications

Used in electronics for its piezoelectric properties, as an abrasive, in glassmaking, and frequently as a gemstone in jewelry or for decorative ornamental carvings.

Geological facts

Quartz is one of the most abundant minerals in Earth's continental crust. Historically, the first 'sunglasses' were made from flat panes of smoky quartz in 12th century China.

Field identification & locations

Identify in the field by its hardness (it will scratch glass), its lack of cleavage, and its characteristic conchoidal fracture. Commonly found in granite outcroppings or as loose pebbles in riverbeds.

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