sedimentary
Crushed Limestone and Calcite
Calcium Carbonate (CaCO3)
Hardness: 3 (Mohs scale); Color: ranges from grey, tan, to white; Luster: dull to vitreous; Crystal structure: Trigonal (often massive/granular); Cleavage: Rhombohedral (perfect)
- Hardness
- 3 (Mohs scale)
- Color
- ranges from grey, tan, to white
- Luster
- dull to vitreous
Identified More sedimentary →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3 (Mohs scale); Color: ranges from grey, tan, to white; Luster: dull to vitreous; Crystal structure: Trigonal (often massive/granular); Cleavage: Rhombohedral (perfect)
Formation & geological history
Formed in marine environments from the accumulation of shell, coral, and algal debris. These specific pieces are likely sourced from a local quarry and processed as aggregate (crushed stone).
Uses & applications
Used primarily in construction for road base, concrete production, drainage, and landscape ground cover. The larger white specimen on the right may be massive quartz or calcite quartz veins.
Geological facts
Limestone occupies about 10% of the total volume of all sedimentary rocks. It is highly reactive with acid, fizzing vigorously when in contact with dilute hydrochloric acid.
Field identification & locations
Identify by its light grey color, blocky fracture, and tendency to react with weak acids. It is ubiquitous in construction sites and riverbeds in limestone-heavy regions.
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