What Are Rock-Forming Minerals? - Geology
The Most Abundant Minerals in Earth's Crust: Known as the "common rock-forming minerals", they are minerals present at the time of a rock's formation and are important minerals in determining the rock's identity. Relative abundance percentages from Ronov and Yaroshevsky; Chemical Composition of the Earth's Crust; American Geophysical Union Monograph Number 13, Chapter 50, 1969.