What kinds of rocks are in the earths crust?
Ninety percent of the rocks found in the earth’s crust contain silicates. These minerals include quartz, potassium feldspar, plagioclase feldspar, muscovite, garnet, biotite, etc. Nonsilicate minerals such as carbonates and halides are also present. These minerals are found in coral reefs, marble, halite, and gypsum. Oxides are also found and include rocks like hematite and magneitte. The last remaining group of rocks are sulfides, which include pyrite and galena.
