mineral

Quartz (Milky or Cloudy variety)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Translucent white to milky; Luster: Vitreous (glassy) to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Translucent white to milky
Luster: Vitreous (glassy) to greasy

Identified March 1, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Translucent white to milky; Luster: Vitreous (glassy) to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed through the cooling and crystallization of silica-rich magma or hydrothermal veins. It can be found in a wide variety of geological environments ranging from igneous pegmatites to sedimentary riverbeds and metamorphic rocks.

Uses & applications

Used in the production of glass, ceramics, and abrasives. In electronics, it is used for its piezoelectric properties. High-clarity specimens are used in jewelry and lapidary art.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz gets its characteristic white color from microscopic inclusions of gas or liquid trapped during crystal growth.

Field identification & locations

Identify in the field by its inability to be scratched by a steel pocket knife and its characteristic 'broken glass' (conchoidal) fracture pattern. It is commonly found in gravel pits, mountain outcrops, and stream beds globally.

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