mineral

Milky quartz (rough quartz fragment)

Quartz, silicon dioxide (SiO₂)

AI-generated identification · may be incorrect

Hardness 7 Mohs; translucent to transparent, colorless to milky white, with a vitreous luster. It has a trigonal crystal structure and indistinct cleavage, commonly breaking with conchoidal fractures; the specimen appears naturally rough and fractured.

Identified September 13, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich fluids crystallize in veins, cavities, and igneous or metamorphic rocks. Quartz spans most of Earth’s geological history and is found in environments from Precambrian rocks to modern hydrothermal deposits.

Uses & applications

Used extensively in glass, ceramics, electronics, abrasives, and engineered stone; transparent pieces may be cut as gemstones. Milky fragments are mainly collected or used decoratively.

Geological facts

Quartz is one of Earth’s most abundant minerals and is piezoelectric, generating an electrical charge under pressure.

Field identification & locations

Identify it by its glassy appearance, lack of cleavage, conchoidal fracture, and inability to scratch it with a steel knife; it should scratch ordinary glass. Common worldwide, especially in granite, pegmatite, quartz veins, and geodes.