mineral

Milk Quartz (Common White Quartz)

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale. Color: Milky white to opaque. Luster: Vitreous to greasy. Crystal Structure: Hexagonal/Trigonal. Cleavage: None (conchoidal fracture). Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Milky white to opaque
Luster: Vitreous to greasy

Identified February 17, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale. Color: Milky white to opaque. Luster: Vitreous to greasy. Crystal Structure: Hexagonal/Trigonal. Cleavage: None (conchoidal fracture). Specific Gravity: 2.65.

Formation & geological history

Formed through the crystallization of silica-rich hydrothermal solutions or cooling of igneous magma. The milky appearance is caused by microscopic inclusions of gas or liquid trapped during crystal growth. Can be found in rocks from almost any geological age.

Uses & applications

Used widely in glass manufacturing, electronics (due to piezoelectric properties), construction as aggregate, and in landscaping. While common, it is also popular among rockhounders for lapidary work and tumbled stones.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. 'Milky Quartz' specifically gets its white color from tiny bubbles of fluids trapped within the crystal structure, similar to how bubbles in ice make it look white.

Field identification & locations

Identify in the field by its hardness (it will scratch glass), lack of cleavage, and waxy/vitreous luster. Common in veins within granite or as water-worn pebbles in streams. It is a fundamental 'indicator mineral' for prospectors looking for gold-bearing veins.

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