Non-clastic rocks have chemical or organic origins. Names of non-clastic rocks are based on their compositions.
• A calcite-rich rock with many fossils is called a fossiliferous limestone.
• Microcrystalline quartz is called chert. The red variety of chert is called jasper. Dark gray to black chert is called flint.
• The carbon-rich rock formed from ancient plant material is called coal.
Left: fossiliferous limestone; right: chert (Photographs by Parvinder Sethi)
Coal (Photograph by Parvinder Sethi)
Sedimentary rocks with non-clastic texture include fossiliferous limestone (above left), chert (above right) and coal (right). All three of these rock types can be found in Virginia.