mineral

Quartz crystal (likely included or coated quartz)

Quartz, silicon dioxide (SiO₂)

AI-generated identification · may be incorrect

Mohs hardness 7; colorless to smoky gray with black mineral inclusions, vitreous luster, and a hexagonal crystal structure. It shows conchoidal fracture rather than cleavage; visible faces appear partly polished or naturally fractured.

Identified August 25, 2026More mineral →

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Physical properties

Formation & geological history

Quartz crystallizes from silica-rich hydrothermal fluids or late-stage igneous cavities, commonly during the Paleozoic to Cenozoic but potentially much older. The dark inclusions may be carbonaceous material, iron/manganese oxides, or another mineral; the photograph alone cannot determine the variety.

Uses & applications

Used for glass, electronics, abrasives, and ornamental or lapidary objects; transparent attractive pieces may be sold as display specimens or jewelry rough.

Geological facts

Quartz is one of Earth’s most abundant minerals and is piezoelectric. Dark inclusions and internal fractures can create strong reflective patterns under light.

Field identification & locations

Identify by glassy luster, lack of cleavage, hardness sufficient to scratch ordinary glass, and a white streak. Common sources include Brazil, Madagascar, Arkansas, China, and Alpine regions; confirm inclusions with magnification or testing.