sedimentary
Limestone
Sedimentary carbonate rock (CaCO3)
AI-generated identification · may be incorrectHardness of 3 on the Mohs scale, typically gray, tan, or white with a dull to earthy luster. Composed primarily of calcite and aragonite with microcrystalline to macrocrystalline structure.
Identified More sedimentary →
Explore Limestone in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness of 3 on the Mohs scale, typically gray, tan, or white with a dull to earthy luster. Composed primarily of calcite and aragonite with microcrystalline to macrocrystalline structure.
Formation & geological history
Formed through the accumulation and compaction of marine organism shells, coral, and algal debris over millions of years in shallow marine environments.
Uses & applications
Widely used in construction, cement production, agriculture for soil neutralization, and as a dimension stone.
Geological facts
Limestone frequently contains well-preserved fossils and dissolves slowly in acidic water, creating dramatic cave systems and karst topography.
Field identification & locations
Easily identified by its characteristic effervescence when exposed to hydrochloric acid. Found worldwide in regions with ancient marine deposition.
More like this
Other sedimentary specimens
Fossil-bearing concretion, possibly containing a fossil shell or other organic inclusion
Calcareous concretion; exact fossil and host-rock composition are not identifiable from the image
fossil
Fossiliferous Sedimentary Rock
Sedimentary limestone with invertebrate fossil imprint
fossil
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sandstone
Arenite
sedimentary
Shale
Shale (clastic sedimentary rock)
sedimentary
Shale (or Mudstone/Siltstone)
Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
sedimentary