mineral

Quartz (Milky/Common Quartz)

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: White to creamy tan/yellow; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: White to creamy tan/yellow
Luster: Vitreous to greasy

Identified April 6, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: White to creamy tan/yellow; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed through the crystallization of silica-rich magma or from hydrothermal veins. It is found in almost all geological environments including igneous, metamorphic, and sedimentary settings.

Uses & applications

Used widely in glassmaking, electronics (piezoelectric properties), abrasives, construction as aggregate, and is popular among recreational rock collectors.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Pure quartz is clear, but tiny fluid inclusions trapped during growth give milky quartz its cloudy white appearance.

Field identification & locations

Identify in the field by its hardness (it will scratch glass), its lack of cleavage, and its characteristic waxy/glassy appearance. It is extremely weather-resistant and is often found in riverbeds or as residual chunks in soil.