sedimentary
Limestone (River Pebble)
Calcium Carbonate (CaCO3)
Hardness 3 on Mohs scale, grayish-white to tan color, dull to earthy luster, microcrystalline, reacts strongly with dilute hydrochloric acid.
Identified More sedimentary →
Explore Limestone (River Pebble) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness 3 on Mohs scale, grayish-white to tan color, dull to earthy luster, microcrystalline, reacts strongly with dilute hydrochloric acid.
Formation & geological history
Formed in shallow marine environments from the accumulation of organic debris, shell fragments, and calcium carbonate precipitation. Later weathered and rounded by river action.
Uses & applications
Used in construction as aggregate, in lime manufacturing, soil neutralization, and as common decorative garden stones.
Geological facts
Limestone makes up about 10% of the total volume of all sedimentary rocks. It is the primary component of karst landscapes which form caves and sinkholes.
Field identification & locations
Easily identified in the field by its softness relative to quartz and its effervescence when exposed to acid. Commonly found in stream beds, river banks, and exposed sedimentary rock formations worldwide.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sedimentary Sandstone
Arenite (Sedimentary Rock)
sedimentary
Fossiliferous Concretion
Septarian Concretion containing Brachiopods/Crinoids
fossil
Shale
Shale (clastic sedimentary rock)
sedimentary
Shale
Sedimentary Shale
sedimentary
Shale and Pebble Fragment
Sedimentary Rock (Mudstone/Shale with Silica Pebble)
sedimentary