A crystal with a well-defined shape, such as a cube, probably:

A) does not reflect the arrangement of atoms in the lattice
B) grew early and so was forced to grow around other minerals
C) does not have a well-defined cleavage
D) will react with dilute hydrochloric acid
E) none of these

Crystal

A solid material whose atoms are arranged in highly ordered, repeating patterns extending in all three spatial dimensions.

Cleavage

The tendency of a mineral to break along flat planar surfaces as determined by the mineral’s crystal structure, often enhancing its gem quality.

Atoms

The basic units of matter consisting of a nucleus surrounded by electrons, making up all chemical elements.