sedimentary
Gray Limestone
Calcium Carbonate (CaCO3)
AI-generated identification · may be incorrectHardness: 3 (Mohs scale), Color: Dark gray to bluish-gray, Luster: Dull to earthy, Crystal Structure: Trigonal (microcrystalline), Cleavage: None/Conchoidal fracture, Specific Gravity: 2.5-2.7
Identified More sedimentary →
Explore Gray 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: Dark gray to bluish-gray, Luster: Dull to earthy, Crystal Structure: Trigonal (microcrystalline), Cleavage: None/Conchoidal fracture, Specific Gravity: 2.5-2.7
Formation & geological history
Formed in marine environments through the accumulation of shell, coral, algal, and fecal debris. It can also form through chemical precipitation from calcium-rich waters.
Uses & applications
Extensively used in construction as road base, aggregate for concrete, architectural stone, and as a raw material in cement manufacture. Also used in soil conditioning and as a flux in steel making.
Geological facts
Limestone covers about 10% of the total land area of the Earth. Most of our world's oil and natural gas reservoirs are found in porous limestone deposits.
Field identification & locations
Identify by its reaction (fizzing) when exposed to dilute hydrochloric acid. It is often found in massive beds and is a primary component of karst landscapes with caves and sinkholes.
More like this
Other sedimentary specimens
Fossiliferous Sedimentary Rock
Sedimentary limestone with invertebrate fossil imprint
fossil
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Quartz pebble
Silicon dioxide (SiO2)
sedimentary
Generic Pebble / Rock Fragment
Lithic fragment / Weathered rock
sedimentary
Sedimentary Sandstone
Arenite (Sedimentary Rock)
sedimentary
Shale (or Mudstone/Siltstone)
Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
sedimentary