mineral

Tumbled yellow calcite (probable)

Calcite — calcium carbonate, CaCO₃

AI-generated identification · may be incorrect

Pale honey-yellow, translucent to opaque, with a vitreous-to-pearly luster and cloudy internal texture; Mohs hardness 3, rhombohedral crystal structure, and perfect rhombohedral cleavage. The rounded shape indicates human tumbling and polishing.

Identified August 22, 2026More mineral →

Explore Tumbled yellow calcite (probable) in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Likely formed in hydrothermal veins, limestone cavities, or evaporitic deposits through precipitation of calcium carbonate; the specimen’s exact geological age cannot be determined visually. Common sources include Mexico, Brazil, and the United States.

Uses & applications

Used for cement, lime, aggregate, and chemical production; attractive transparent pieces are collected or carved, though this small tumbled specimen has little jewelry value.

Geological facts

Calcite effervesces readily in cold dilute hydrochloric acid and can often be scratched with a steel knife. Similar yellow tumbled material may be aragonite, yellow fluorite, or dyed quartz, so identification is provisional without testing.

Field identification & locations

Field clues include very low hardness, rhombohedral cleavage, and strong acid reaction; compare with quartz, which is much harder and does not fizz. Common value is about $1–$8 for a small tumbled stone; exceptional transparent specimens cost more.