Sedimentary rocks are also classified based on their mineral composition. Common minerals in sedimentary rocks include:
• Quartz
• Calcite
• Dolomite
Quartz is an extremely stable mineral, both mechanically and chemically. It is a major component of sandstone and chert. This photograph shows a sample of chert.
Chert (Photograph by Parvinder Sethi)
Calcite forms limestone through chemical and biological processes. Limestone is a very common sedimentary rock. The small gray mineral grains and the white fossil grains in this rock are both composed of calcite.
Fossiliferous limestone (Photograph by Parvinder Sethi)