Stephan’s mother is a mineralogist, and sometimes she brings home samples to study. Stephan observesand compares these minerals. He knows minerals form in several ways. He is especially interested in the minerals that form from volcanic activity and the kinds of crystals they form. What determines crystal size in minerals formed by lava or magma?
A. the kind of mineral that formed
B. the amount of material available
C. the rate at which the minerals cooled
D. the materials in the lava or magma