sedimentary

Oolitic Limestone

Oolite (Sedimentary Calcium Carbonate)

AI-generated identification · may be incorrect

Hardness: 3-4 (Mohs); Color: White, cream, gray; Luster: Dull to earthy; Structure: Granular, composed of tiny spherical grains called ooids (<2mm); Specific Gravity: 2.5-2.7.

Hardness: 3-4 (Mohs)
Color: White, cream, gray
Luster: Dull to earthy

Identified April 11, 2026More sedimentary →

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Physical properties

Hardness: 3-4 (Mohs); Color: White, cream, gray; Luster: Dull to earthy; Structure: Granular, composed of tiny spherical grains called ooids (<2mm); Specific Gravity: 2.5-2.7.

Formation & geological history

Formed in warm, shallow, agitated marine environments where calcium carbonate precipitates around a nucleus (like a sand grain or shell fragment) in concentric layers. Most commonly formed during the Jurassic or Carboniferous periods.

Uses & applications

Used in construction as a building stone (Portland stone), as a lime source for agriculture, in the manufacture of glass, and as a flux in steel making.

Geological facts

The name 'Oolite' comes from the Greek word 'oon' for egg, because the texture resembles fish roe. Many famous buildings, including Buckingham Palace and St. Paul's Cathedral, are built with oolitic limestone.

Field identification & locations

Identify by looking for small, egg-shaped grains (ooids) that are visible to the naked eye or with a hand lens. It will fizz strongly when in contact with dilute hydrochloric acid. Commonly found in areas like the Cotswolds in England or parts of the midwestern United States.