Rock Identifier
Milky quartz (Quartz (silicon dioxide, SiO₂)) — mineral
mineral

Milky quartz

Quartz (silicon dioxide, SiO₂)

AI-generated identification · may be incorrect

Typically white, translucent, and vitreous to waxy, with irregular fracture and no cleavage; Mohs hardness 7, specific gravity about 2.65, trigonal crystal structure. The specimen appears as a rough, rounded white quartz fragment, though calcite is a possible visual look-alike.

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Physical properties

Typically white, translucent, and vitreous to waxy, with irregular fracture and no cleavage; Mohs hardness 7, specific gravity about 2.65, trigonal crystal structure. The specimen appears as a rough, rounded white quartz fragment, though calcite is a possible visual look-alike.

Formation & geological history

Forms in igneous and metamorphic rocks, hydrothermal veins, and pegmatites when silica-rich fluids crystallize; occurrences range from Precambrian to modern geological settings.

Uses & applications

Used as a silica source for glass, ceramics, and engineered stone; attractive pieces are sold as inexpensive mineral specimens, but this rough fragment has little jewelry value.

Geological facts

Its cloudy appearance results from microscopic fluid inclusions, fractures, or dispersed impurities. Quartz is highly resistant to weathering and commonly accumulates in stream gravels and soils.

Field identification & locations

Common worldwide, including Brazil, Madagascar, the United States, and Alpine regions. It can scratch ordinary glass; unlike calcite, it does not fizz with dilute hydrochloric acid, though a hardness or acid test should be performed carefully.