mineral

Quartz (milky quartz), possibly calcite

Quartz: SiO₂; visual identification is uncertain because the specimen is wet and lacks diagnostic crystal faces

AI-generated identification · may be incorrect

Creamy white, translucent to opaque, with a vitreous-to-waxy luster and likely massive texture. Quartz has Mohs hardness 7, no cleavage, and specific gravity about 2.65; calcite would be softer (Mohs 3) with prominent rhombohedral cleavage.

Identified August 11, 2026More mineral →

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Physical properties

Formation & geological history

Likely a naturally weathered mineral fragment from a quartz-rich vein, pegmatite, or sediment; its precise geological age and formation environment cannot be determined from the image.

Uses & applications

Quartz is used in glass, ceramics, electronics, abrasives, and ornaments; attractive pieces may be collected. Calcite is widely used in cement, lime, aggregate, and as a carbonate mineral specimen.

Geological facts

A steel knife should not scratch quartz, while quartz can scratch glass; calcite reacts readily with dilute hydrochloric acid or vinegar, though vinegar may be weak. The irregular shape suggests stream transport or breakage.

Field identification & locations

Common in stream gravels worldwide, especially near granitic or metamorphic rocks. Test hardness, inspect for cleavage, and use acid cautiously; definitive identification may require streak, density, or chemical testing.