Naturally occurring, solid substances that have a crystalline structure and a defined chemical composition are called
a. rocks.
b. minerals.
c. sediments.
d. conglomerates.

The correct answer is B.

A mineral is defined as a naturally occurring substance that has a definite chemical composition  and crystal structure.

In order for a substance to be called a mineral, it must have all the four characters described in the definition.

- a mineral is always a solid and has a definite shape and volume.

- most minerals are made of two or more elements chemically combined to form a compound. It may also be made of a single element e.g.  gold, copper or sulphur.

-  all minerals have a characteristic crystal structure.

- minerals are grouped according to their chemical composition or makeup

answer; i believe the correct answer is (general);