mineral

Likely tumbled yellow calcite or aragonite

Calcite (CaCO₃) or aragonite (CaCO₃)

AI-generated identification · may be incorrect

Small polished, pale-yellow translucent specimen with a waxy to pearly luster; calcite has Mohs hardness 3, rhombohedral cleavage, and aragonite hardness 3.5–4. The image lacks enough detail for a definitive distinction.

Identified September 20, 2026More mineral →

Explore Likely tumbled yellow calcite or aragonite 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

Calcium-carbonate minerals form in sedimentary, hydrothermal, cave, and biological environments; aragonite commonly forms in shells and low-temperature deposits. Specimen age cannot be determined from the photograph.

Uses & applications

Used as a decorative or teaching specimen; calcite is important in cement, lime, glass, and agriculture, while aragonite is chiefly ornamental and industrially minor.

Geological facts

Calcite effervesces strongly with dilute hydrochloric acid, whereas aragonite may react more slowly when unpowdered. The irregular bone-like shape appears tumbled or carved rather than naturally crystallized.

Field identification & locations

Common sources include Mexico, the United States, Spain, Morocco, and Namibia. Confirm with a hardness test, streak, and acid reaction; avoid testing valuable specimens visibly.