Minerals must have atoms that are tightly packed together and cannot move freely. Which part of the definition of a mineral does this describe?

Question

A. The requirement that minerals must be naturally occuring.
B. The requirement that minerals must have a defined chemical composition
C. The requirement that minerals must have a defined crystalline structure.
D. The requirement that minerals must be solid

Answer 1

C. The requirement that minerals must have a defined crystalline structure.