mineral

Quartz (Smoky/Rock Crystal)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: transparent to translucent with tan/brownish iron staining; Luster: Vitreous (glassy); Crystal Structure: Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Color: transparent to translucent with tan/brownish iron staining
Luster: Vitreous (glassy)

Identified July 9, 2026More mineral →

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Physical properties

Formation & geological history

Forms in igneous, metamorphic, and sedimentary environments. Typically crystallizes from hydrothermal veins or cooling magmatic bodies. Found globally in a variety of geological ages.

Uses & applications

Used widely in manufacturing glass, electronics (piezoelectric properties), construction aggregates, as well as jewelry and decorative mineral collections.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Its name comes from the German word 'Quarz', which has Slavic origins meaning 'hard'.

Field identification & locations

Identify in the field by its ability to scratch glass, its lack of cleavage, and its vitreous luster. Commonly found in riverbeds, mountains, and as vein-filling material in host rocks.