sedimentary

Limestone

Calcium Carbonate (CaCO3)

Hardness: 3 on Mohs scale; Color: White, gray, or tan (as seen in the cliff); Luster: Dull to earthy; Crystal structure: Trigonal/rhombohedral (as calcite crystals); Specific Gravity: 2.71.

Hardness: 3 on Mohs scale
Color: White, gray, or tan (as seen in the cliff)
Luster: Dull to earthy

Identified December 25, 2025More sedimentary →

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Physical properties

Hardness: 3 on Mohs scale; Color: White, gray, or tan (as seen in the cliff); Luster: Dull to earthy; Crystal structure: Trigonal/rhombohedral (as calcite crystals); Specific Gravity: 2.71.

Formation & geological history

Formed primarily from the accumulation of shell, coral, algal, and fecal debris in warm, shallow marine waters. These specific cliffs in the Mediterranean (likely Capri or similar coastlines) typically date from the Jurassic or Cretaceous periods and were uplifted by tectonic activity.

Uses & applications

Extensively used in construction as building stone, road base, and a key ingredient in cement/concrete. High-purity limestone is used in glass making and as a chemical feedstock.

Geological facts

Limestone landscapes often develop 'karst' topography, creating caves and sinkholes due to the rock's solubility in slightly acidic rainwater. The island of Capri is famously composed almost entirely of this rock.

Field identification & locations

Identify in the field by its реагирование (fizzing) when exposed to a drop of dilute hydrochloric acid. It is commonly found in massive marine sequences; look for visible fossils of shells or coral and its characteristic light-colored weathering pattern on coastal cliffs.