Question

which statement names characteristics of a mineral?
it must be crystalline and have an indefinite chemical composition.
it must be crystalline and have a definite chemical composition.
it must be amorphous and have a definite chemical composition.
it must be amorphous and have an indefinite chemical composition.

Explanation:

A mineral is a naturally - occurring inorganic solid. One of the key characteristics is that it has a definite chemical composition (the relative amounts of its chemical elements are fixed or vary within a narrow range). Also, minerals have an ordered internal atomic arrangement which means they are crystalline (not amorphous, which has a disordered atomic structure).

Answer:

It must be crystalline and have a definite chemical composition.