The eight most common elements in Earth's crust are: O, Si, Al, Fe, Ca, Na, K, and Mg. These elements account for 98% of the atoms in Earth's crust. These eight elements combine chemically with one another to make six main minerals which account for 90% of the minerals in Earth's crust. These minerals, the so-called the rock forming minerals, are: feldspar, pyroxene, amphibole, mica and the last, made up of the two most abundant elements, is
A) galena.
B) gold.
C) hematite.
D) quartz.
