mineral

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: white to off-white, light gray with iron staining; Luster: vitreous to waxy; Crystal structure: hexagonal/trigonal; Cleavage: none (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: white to off-white, light gray with iron staining
Luster: vitreous to waxy

Identified May 16, 2026More mineral →

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Physical properties

Formation & geological history

Forms through the crystallization of molten magma or precipitates from hydrothermal veins. This specimen appears water-worn, likely found in a riverbed or coastal area. Quartz can be from almost any geological age from Precambrian to recent.

Uses & applications

Used in glassmaking, electronics (piezoelectric properties), abrasives, as a flux in metallurgy, and as semi-precious gemstones/collectors items.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz gets its cloudy appearance from microscopic inclusions of fluids that were trapped during the crystal's growth.

Field identification & locations

Identified in the field by its hardness (it will scratch glass), its lack of cleavage, and its waxy luster when weathered. Common in riverbeds and gravel pits worldwide.