mineral

Quartz

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Tan to milky white with iron staining; Luster: Vitreous to greasy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Tan to milky white with iron staining
Luster: Vitreous to greasy

Identified May 27, 2026More mineral →

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Physical properties

Formation & geological history

Forms in a variety of environments, most commonly from the cooling of silica-rich magma or from hydrothermal veins. It is one of the most abundant minerals in the Earth's crust.

Uses & applications

Used in glassmaking, abrasives, electronics (due to piezoelectric properties), and as a gemstone or collector specimen. Small rough pieces are often used in landscaping or construction aggregate.

Geological facts

Quartz is chemically and physically very resistant to weathering. When rocks erode, quartz often remains as sand on beaches or in riverbeds. It is the most common mineral found in the Earth's continental crust.

Field identification & locations

Identify by its hardness (it will scratch glass), its lack of cleavage, and its typical hexagonal crystal form if faces are present. Commonly found in riverbeds, mountains, and desert sands globally.