mineral

Quartz (Milky/Common)

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: White to off-white; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7 (Mohs scale)
Color: White to off-white
Luster: Vitreous to greasy

Identified March 29, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: White to off-white; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Formation & geological history

Formed through the cooling of silica-rich magma or from hydrothermal veins. It is found in a vast range of geological environments spanning from the Precambrian to recent eras.

Uses & applications

Used in glassmaking, abrasives, electronic oscillators (piezoelectric properties), and as a common construction aggregate. Low-grade specimens are primarily used in landscaping.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. It is highly resistant to both chemical and physical weathering, which is why it often persists as sand on beaches.

Field identification & locations

Identify in the field by its ability to scratch glass and its lack of cleavage. It is found globally in almost all rock types. For collectors, look for hexagonal terminations or unusual inclusions.