mineral

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

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

Hardness: 7 on Mohs scale
Color: Opaque white to yellowish
Luster: Vitreous to greasy

Identified April 7, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed through the cooling of magma or by hydrothermal precipitation in veins. Quartz is found in almost all geological ages and environments, particularly in igneous rocks like granite or as a secondary mineral in veins.

Uses & applications

Used in glassmaking, abrasives, decorative stones, electronics (due to piezoelectric properties), and as a gemstone when high quality.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz gets its cloudiness from tiny fluid inclusions of gas and/or liquid trapped during crystal growth.

Field identification & locations

Identify in the field by its hardness (will scratch glass and steel), lack of cleavage, and conchoidal (shell-like) fracture. Extremely common in riverbeds and mountainous terrain.