sedimentary
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Hardness: 3 (Mohs scale); Color: gray to light tan; Luster: dull/earthy; Texture: fine-grained matrix containing visible fossil fragments; Cleavage: none (conchoidal fracture).
- Hardness
- 3 (Mohs scale)
- Color
- gray to light tan
- Luster
- dull/earthy
Identified More sedimentary →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3 (Mohs scale); Color: gray to light tan; Luster: dull/earthy; Texture: fine-grained matrix containing visible fossil fragments; Cleavage: none (conchoidal fracture).
Formation & geological history
Formed in shallow, calm, warm marine waters from the accumulation of shell, coral, algal, and fecal debris. These rocks often date from many geological periods, frequently Paleozoic or Mesozoic eras.
Uses & applications
Used in the production of cement, as a building stone, in road base construction, and as a soil conditioner in agriculture. Small fossiliferous pieces are popular in educational collections.
Geological facts
Limestone makes up about 10% of the total volume of all sedimentary rocks. It is the primary source of lime for the steel industry and chemical applications.
Field identification & locations
Identified by its reaction (fizzing) when exposed to dilute hydrochloric acid and the presence of visible biological remains. Commonly found in areas that were formerly ancient seabeds.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sandstone
Arenite (primarily SiO2)
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
sedimentary