mineral

Clear quartz (rock crystal)

Quartz, silicon dioxide (SiO₂)

AI-generated identification · may be incorrect

Colorless to smoky-clear with a glassy luster and irregular fracture; quartz is trigonal and has no cleavage. Hardness is 7 on the Mohs scale and specific gravity is about 2.65.

Identified September 29, 2026More mineral →

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Physical properties

Colorless to smoky-clear with a glassy luster and irregular fracture; quartz is trigonal and has no cleavage. Hardness is 7 on the Mohs scale and specific gravity is about 2.65.

Formation & geological history

Quartz crystallizes from silica-rich fluids in veins and cavities, and also occurs in many igneous and metamorphic rocks. The pictured fragment alone does not establish its geological age or exact origin.

Uses & applications

Quartz is used in glassmaking, electronics, abrasives, and as a gemstone or mineral specimen.

Geological facts

Quartz is one of Earth’s most abundant minerals; its crystals can form six-sided prisms, though this fragment shows no clear crystal termination.

Field identification & locations

The hand-sized, transparent-to-gray fragment is consistent with quartz, but the photo cannot rule out other clear minerals. Check for hardness (it scratches glass) and lack of cleavage; common sources include quartz veins and pegmatites worldwide.