sedimentary

Likely calcite-rich limestone

Calcite (CaCO₃) in micritic or crystalline limestone; identification from the image is provisional

AI-generated identification · may be incorrect

Cream to pale gray, irregular and partly crystalline surface with a pearly to dull luster. Calcite hardness is 3 Mohs, rhombohedral cleavage, and specific gravity about 2.7; the rock’s texture varies with impurities and grain size.

Identified October 14, 2026More sedimentary →

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Physical properties

Formation & geological history

Limestone forms chiefly from accumulated marine carbonate shells or direct carbonate precipitation, then may recrystallize during burial. Such deposits range from recent to billions of years old; the specimen’s age cannot be determined from the image.

Uses & applications

Limestone is used in cement, aggregate, building stone, and agricultural lime; calcite crystals are collected and sometimes used decoratively.

Geological facts

Calcite effervesces readily in dilute hydrochloric acid; dolomite-rich rocks react more weakly unless powdered.

Field identification & locations

Look for a pale carbonate rock that scratches with a steel knife and fizzes in dilute acid. Limestone occurs widely in former marine basins; this small specimen’s exact locality and identity require testing.