mineral

Quartz

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale), Color: White, tan, or iron-stained brown, Luster: Vitreous to greasy, Crystal structure: Trigonal/Hexagonal, Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Identified July 6, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale), Color: White, tan, or iron-stained brown, Luster: Vitreous to greasy, Crystal structure: Trigonal/Hexagonal, Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Formation & geological history

Formed in almost all geological environments; this specimen is likely a water-worn river stone or driveway gravel piece derived from a hydrothermal vein or pegmatite.

Uses & applications

Used in glassmaking, abrasives, construction aggregates, and as a gemstone when high quality. Industrial uses include electronics and quartz watches.

Geological facts

Quartz is the second most abundant mineral in the Earth's continental crust. It is chemically very stable and resistant to weathering, which is why it is often found as smooth pebbles in riverbeds.

Field identification & locations

Identify in the field by its hardness (it can scratch glass and steel), lack of cleavage, and waxy or glassy appearance. It is found globally in almost every terrain.