mineral

Likely tumbled yellow calcite or quartz

Uncertain; possibly calcite (CaCO₃) or iron-stained quartz (SiO₂)

AI-generated identification · may be incorrect

A small rounded, polished yellow-orange specimen with subdued vitreous to waxy luster. The image does not resolve cleavage, crystal structure, hardness, or specific gravity; calcite is Mohs 3 with rhombohedral cleavage, while quartz is Mohs 7 and lacks cleavage.

Identified August 23, 2026More mineral →

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Physical properties

Formation & geological history

If calcite, it likely formed from carbonate-rich groundwater or hydrothermal veins; if quartz, from silica-rich veins or cavities, with iron oxides producing the yellow color. Geological age cannot be determined from the photograph.

Uses & applications

Tumbled specimens are used for collecting, decoration, and metaphysical displays; calcite has industrial uses in cement and limestone, while quartz is used in glass, abrasives, electronics, and jewelry.

Geological facts

The rounded shape and surface sheen indicate human tumbling or polishing rather than a natural crystal form.

Field identification & locations

Confirm with tests: calcite effervesces with dilute hydrochloric acid and scratches easily with a copper coin; quartz does not react and scratches glass. Common sources include Mexico, Brazil, and the United States.