This image shows some of the most common minerals you'll find in rocks. This pile contains plagioclase feldspar , potassium feldspar , quartz , muscovite mica , biotite mica , amphibole , olivine , and calcite . Click on any mineral for a close up view. Quartz Quartz is one of the most common minerals in the Earth's crust.
Plagioclase is a member of the feldspar mineral family.
Plagioclase feldspars are yet another silicate that contains considerable sodium or calcium. Feldspar crystals are stubby prisms, generally white to gray and a glassy luster . This variety of plagioclase, called albite , is rich in sodium. Potassium feldspar Potassium feldspar is another member of the feldspar mineral family. Feldspar crystals are stubby prisms, often pink to white.