sedimentary
Limestone (specifically a Crushed Aggregate fragment)
Calcium Carbonate (CaCO3)
Hardness: 3 (Mohs scale); Color: White to light grey; Luster: Dull/Earthy; Crystal Structure: Trigonal (as calcite); Cleavage: Perfect rhombohedral; Specific Gravity: 2.7.
- Hardness
- 3 (Mohs scale)
- Color
- White to light grey
- Luster
- Dull/Earthy
Identified More sedimentary →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3 (Mohs scale); Color: White to light grey; Luster: Dull/Earthy; Crystal Structure: Trigonal (as calcite); Cleavage: Perfect rhombohedral; Specific Gravity: 2.7.
Formation & geological history
Formed through the accumulation of shell, coral, algal, and fecal debris in marine environments. This specific specimen appears to be a fragment of mechanically crushed quarry stone used in construction.
Uses & applications
Primary source of lime for cement, used as a soil conditioner in agriculture, road base aggregate, and white pigment or filler in toothpaste and plastics.
Geological facts
Limestone makes up about 10% of the total volume of all sedimentary rocks. It is the primary building block of the Great Pyramids of Giza.
Field identification & locations
Identify in the field by its softness (can be scratched by a copper coin) and its effervescence (bubbles) when a drop of weak acid such as vinegar is applied. Very common in regions with ancient seabed history.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Sandstone Grain
Clastic Sedimentary Rock Grain (SiO2 dominated)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Sandstone
Arenite
sedimentary