mineral

Orange calcite

Calcite (CaCO₃), likely honey/orange calcite

AI-generated identification · may be incorrect

Typically Mohs hardness 3, vitreous to pearly luster, translucent orange coloration, rhombohedral cleavage, and trigonal crystal structure; reacts vigorously with dilute hydrochloric acid. The rough, waxy-looking specimen is consistent with calcite, though color can also result from iron impurities.

Identified August 7, 2026More mineral →

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Physical properties

Formation & geological history

Forms mainly in sedimentary limestone, hydrothermal veins, and cave deposits through precipitation from carbonate-rich fluids; individual specimens may range from recent to Paleozoic or younger host-rock ages. Common sources include Mexico, Brazil, the United States, and China.

Uses & applications

Used in cement, lime, agricultural soil treatment, fillers, and optical instruments; orange calcite is also collected and sold as a decorative mineral. It is generally unsuitable for jewelry because of its softness and cleavage.

Geological facts

Its strong acid reaction and very low hardness distinguish it from quartz, which it can resemble. Orange hues commonly reflect inclusions or iron-related coloration.

Field identification & locations

Identify by scratching with a steel knife or copper coin, testing acid reaction, and observing rhombohedral cleavage; avoid vinegar as it may react weakly. Common localities include Mexican and Brazilian carbonate deposits.