Sedimentary Rocks

Sedimentary rocks are categorized into two broad groups:

Quartz (SiO2) is one of the most important minerals.  It occurs only in continental crust, so when it it found in sediments, it indicates the source of at least some of the sediment.  Because quartz is hard, it is physically durable, and because it does not easily react (breakdown or dissolve), it is common in environments like beaches.

Last revision 8/23/2016