sedimentary
Limestone
Calcium Carbonate (CaCO3)
Hardness: 3 on Mohs scale; Color: Tan, beige, or white; Luster: Dull/Earthy; Crystal Structure: Trigonal (microcrystalline); Cleavage: None in rock form; Specific Gravity: 2.5-2.7
- Hardness
- 3 on Mohs scale
- Color
- Tan, beige, or white
- Luster
- Dull/Earthy
Identified More sedimentary →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3 on Mohs scale; Color: Tan, beige, or white; Luster: Dull/Earthy; Crystal Structure: Trigonal (microcrystalline); Cleavage: None in rock form; Specific Gravity: 2.5-2.7
Formation & geological history
Formed primarily from the accumulation of shell, coral, algal, and fecal debris in warm, shallow marine waters. Most specimens date from various eras across the Phanerozoic Eon.
Uses & applications
Used extensively in construction (road base, concrete), agriculture (soil conditioner), and as a primary raw material for cement production.
Geological facts
Limestone makes up about 10% of the total volume of all sedimentary rocks on Earth. It is the primary rock type found in karst landscapes, which feature caves and sinkholes.
Field identification & locations
Identify in the field by its softness (can be scratched by a copper coin) and its vigorous reaction (fizzing) when exposed to a drop of dilute hydrochloric acid or strong vinegar.
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