sedimentary
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Hardness: 3 (Mohs scale); Color: Gray to tan; Luster: Dull/Earthy; Crystal structure: Orthorhombic or Trigonal (microcrystalline matrix); Cleavage: None; Specific gravity: 2.3-2.7
- Hardness
- 3 (Mohs scale)
- Color
- Gray to tan
- Luster
- Dull/Earthy
Identified More sedimentary →
Explore Fossiliferous Limestone in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3 (Mohs scale); Color: Gray to tan; Luster: Dull/Earthy; Crystal structure: Orthorhombic or Trigonal (microcrystalline matrix); Cleavage: None; Specific gravity: 2.3-2.7
Formation & geological history
Formed in shallow marine environments through the accumulation of shell, coral, and algal debris. This specimen appears to contain crinoid stem fragments or small shells from the Paleozoic era.
Uses & applications
Used in construction as aggregate, in the manufacture of cement, as a decorative stone, and in agriculture to neutralize soil acidity.
Geological facts
Limestone makes up about 10% of the total volume of all sedimentary rocks. It often contains well-preserved fossils that provide a window into ancient ocean life.
Field identification & locations
Identify in the field by its grainy texture and the presence of visible fossils or 'rings'. It will effervesce (fizz) when exposed to a drop of cold dilute hydrochloric acid. Commonly found in former seabed regions.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Cone-in-cone structure (Limestone)
Cone-in-cone structure (Secondary Sedimentary Structure)
sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Sandstone Grain
Clastic Sedimentary Rock Grain (SiO2 dominated)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary