sedimentary
Oolitic Limestone
Oolite (Sedimentary Calcium Carbonate)
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 More sedimentary →
Identify your own rocks.
Get a report just like this from any photo, free.
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.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Sandstone (Quartz-rich)
Arenite (SiO2)
sedimentary
Sandstone (with man-made markings)
Arenite (composed primarily of Quartz, SiO2)
sedimentary