mineral

Quartz on Matrix

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: Colorless to white (milky); Luster: Vitreous (glassy); Crystal Structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: Colorless to white (milky)
Luster: Vitreous (glassy)

Identified January 13, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: Colorless to white (milky); Luster: Vitreous (glassy); Crystal Structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed through hydrothermal activity where silica-rich fluids permeate rock cavities and cool, or crystallized from cooling magma. This specimen shows quartz crystals growing on a darker host rock (matrix).

Uses & applications

Used in glassmaking, abrasives, and as semi-precious gemstones in jewelry. High-purity quartz is essential in electronics for its piezoelectric properties and in the manufacturing of optical instruments.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Pure quartz is known as rock crystal, while impurities cause varieties like amethyst (purple), citrine (yellow), and rose quartz (pink).

Field identification & locations

Identify in the field by its hardness (will scratch glass and steel), glassy luster, and lack of cleavage. Commonly found in all geological environments, particularly in igneous veins and sedimentary deposits.