Which of these statements is correct about wood and common salt?

a.) both wood and common salt are minerals because they are natural, solid materials.

b.) both wood and common salt are not minerals because they are not formed under the ground.

c.) common salt is a mineral because it has a definite crystal structure but wood is not a mineral because it is organic.

d.) common salt is not a mineral because it is not formed under the ground but wood is a mineral because it has a definite composition.

Option (C) is the correct answer.

Explanation:

Minerals are inorganic substances which have certain characteristic shape or structure along with homogeneous chemical composition.

It is not necessary that a mineral should be formed under the ground.

Substances which have carbon atoms in their structure are called organic compounds.  The structure of wood has carbon atoms attached thus, wood is an organic compound.

Therefore, we can conclude that common salt is a mineral because it has a definite crystal structure but wood is not a mineral because it is organic.