sedimentary
Sidewalk Chalk
Calcium Carbonate (CaCO3) / Gypsum
AI-generated identification · may be incorrectHardness of 1 on Mohs scale, typically white or dyed various pastel colors, earthy luster, powdery texture.
Identified More sedimentary →
Explore Sidewalk Chalk in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness of 1 on Mohs scale, typically white or dyed various pastel colors, earthy luster, powdery texture.
Formation & geological history
Manufactured from natural sedimentary limestone deposits or mined gypsum, formed from compressed marine microfossils over millions of years.
Uses & applications
Used primarily by children for drawing on outdoor paved surfaces and sidewalks.
Geological facts
Natural chalk is a soft, porous, sedimentary rock, a form of limestone composed of the mineral calcite.
Field identification & locations
Easily identified by its soft, powdery consistency and ability to leave a mark on hard surfaces.
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