mineral

Likely calcite or quartz fragment

Uncertain from image; calcite (CaCO₃) is the leading possibility, with quartz (SiO₂) another possibility

AI-generated identification · may be incorrect

Small irregular white, opaque-to-translucent fragment with a dull to weakly vitreous luster. Calcite has Mohs hardness 3, rhombohedral cleavage, and specific gravity 2.71; quartz has hardness 7, no cleavage, and specific gravity 2.65.

Identified August 11, 2026More mineral →

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Physical properties

Formation & geological history

Could be a weathered or broken mineral vein fragment, commonly formed in hydrothermal veins or sedimentary cavities. Exact age and geological setting cannot be determined from the photograph.

Uses & applications

Calcite is used in cement, lime, aggregates, and industrial filler; quartz is used in glass, ceramics, electronics, and abrasives. This fragment has negligible commercial value.

Geological facts

A vinegar or dilute hydrochloric-acid test can distinguish calcite: it effervesces, while quartz does not. The specimen’s small size and lack of visible crystal faces prevent confident identification.

Field identification & locations

Commonly found in limestone, marble, geodes, and mineral veins worldwide; quartz is likewise widespread. Test hardness against a steel blade or glass, inspect cleavage, and use acid only with eye protection.