
sedimentary
Limestone (Weathered)
Calcium Carbonate (CaCO3)
AI-generated identification · may be incorrectHardness: 3 on the Mohs scale. Color: Grayish-brown, weathered gray. Luster: Dull or earthy. Crystal structure: Microcrystalline or cryptocrystalline calcite. Cleavage: Perfect rhombohedral cleavage in pure crystals, but often absent or obscured in dense varieties. Specific gravity: 2.7 to 2.9.
- Hardness
- 3 on the Mohs scale
- Color
- Grayish-brown, weathered gray
- Luster
- Dull or earthy
Identified More sedimentary →
Explore Limestone (Weathered) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3 on the Mohs scale. Color: Grayish-brown, weathered gray. Luster: Dull or earthy. Crystal structure: Microcrystalline or cryptocrystalline calcite. Cleavage: Perfect rhombohedral cleavage in pure crystals, but often absent or obscured in dense varieties. Specific gravity: 2.7 to 2.9.
Formation & geological history
Formed through the accumulation and compaction of organic remains such as shells, coral, and algal debris, or through the chemical precipitation of calcium carbonate from marine water over millions of years. This particular specimen shows extensive dissolution features (karst weathering/solution pits).
Uses & applications
Used widely in construction (aggregate, cement, building stone), agriculture (soil conditioning), and industrial chemical processes.
Geological facts
Limestone landscapes often feature caves, sinkholes, and underground drainage systems due to the high solubility of calcium carbonate in slightly acidic groundwater.
Field identification & locations
Easily identifiable in the field by its characteristic reaction to dilute hydrochloric acid (it effervesces or fizzes) and its lower hardness, allowing it to be scratched easily with a knife.
More like this
Other sedimentary specimens
Fossiliferous Sedimentary Rock
Sedimentary limestone with invertebrate fossil imprint
fossil
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sandstone
Arenite
sedimentary
Quartz pebble
Silicon dioxide (SiO2)
sedimentary
Shale
Shale (clastic sedimentary rock)
sedimentary
Shale (or Mudstone/Siltstone)
Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
sedimentary