sedimentary
Limestone Pebble
Limestone (Calcium Carbonate - CaCO3)
AI-generated identification · may be incorrectHardness: 3 on Mohs scale; Color: light gray to off-white; Luster: dull/earthy; Structure: microcrystalline; Cleavage: none; Specific Gravity: 2.5-2.7
- Hardness
- 3 on Mohs scale
- Color
- light gray to off-white
- Luster
- dull/earthy
Identified More sedimentary →
Explore Limestone 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; Color: light gray to off-white; Luster: dull/earthy; Structure: microcrystalline; Cleavage: none; Specific Gravity: 2.5-2.7
Formation & geological history
Formed in clear, warm, shallow marine waters through the accumulation of shell, coral, algal, and fecal debris. This specimen has been rounded and smoothed by water erosion.
Uses & applications
Commonly used as aggregate for cement, road base, or in aquariums and landscaping. High-purity limestone is used in glass making and agriculture.
Geological facts
Limestone makes up about 10% of the total volume of all sedimentary rocks on Earth. This specific pebble shape, known as a 'clast', indicates it has spent significant time in a high-energy water environment like a beach or riverbed.
Field identification & locations
Identify in the field by its softness (can be scratched by a steel nail) and its reaction to dilute hydrochloric acid (it will fizz/effervesce).
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