mineral
Rock crystal (clear quartz)
Quartz, silicon dioxide (SiO₂), likely milky/included quartz
AI-generated identification · may be incorrectHardness 7 Mohs; colorless to translucent white with glassy luster. Trigonal crystal structure, commonly showing conchoidal fracture and no cleavage; density about 2.65 g/cm³. The rounded shape appears naturally worn or roughly broken, not a well-formed crystal.
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Physical properties
Hardness 7 Mohs; colorless to translucent white with glassy luster. Trigonal crystal structure, commonly showing conchoidal fracture and no cleavage; density about 2.65 g/cm³. The rounded shape appears naturally worn or roughly broken, not a well-formed crystal.
Formation & geological history
Forms from silica-rich hydrothermal fluids, pegmatites, and cavities in igneous or metamorphic rocks; it may also occur as transported alluvial gravel. Quartz is geologically widespread and ranges from Precambrian to modern deposits.
Uses & applications
Used for glass, ceramics, abrasives, electronics, and engineered quartz; clear attractive pieces are sold as decorative or metaphysical specimens. This ordinary, uncrystallized piece usually has modest commercial value.
Geological facts
The image does not show diagnostic crystal faces, so identification is approximate; it could also be a pale quartz-rich rock or calcite. A scratch test and acid test would help distinguish them.
Field identification & locations
Common worldwide, including parts of Nigeria near 8.5°N, 8.5°E, where quartz occurs in crystalline basement rocks and stream deposits. Quartz will not be scratched by a steel knife, while calcite will fizz in dilute hydrochloric acid and is much softer (Mohs 3).
