mineral

Quartz (milky/clear rough quartz)

Quartz, silicon dioxide (SiO₂)

AI-generated identification · may be incorrect

Hardness 7 Mohs; colorless to milky gray, vitreous luster, translucent edges, conchoidal fracture, and no cleavage. It has a trigonal crystal structure, though this fragment shows no complete crystal form.

Identified August 29, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich fluids crystallize in veins, cavities, and igneous rocks; individual specimens may range from Precambrian to recent hydrothermal deposits. The rough, fractured piece is consistent with common vein quartz.

Uses & applications

Used in glass, ceramics, engineered stone, abrasives, electronics, and watches; attractive clear pieces are collected or cut as gemstones. This specimen is mainly a common collector sample.

Geological facts

Quartz is the second-most abundant mineral in Earth’s continental crust and is piezoelectric, producing an electric charge under pressure.

Field identification & locations

Identify by its glassy appearance, hardness (scratches ordinary glass), lack of cleavage, and conchoidal fracture; common worldwide, especially in hydrothermal veins and granite-rich regions. A hardness or streak test should be done on an inconspicuous area.