A naturally occurring solid chemical element or inorganic compound with a crystal structure

Mineral

Explanation:

Mineral:-

Mineral is defined as the naturally occurring inorganic solid which a very definite crystalline geometry and structure. All the minerals in the nature contain one or more than one element. Quartz which is a mineral is made up of silicon as well as oxygen atoms. Other examples of minerals are feldspar, mica, calcite, and amphibole.

Hence, the answer to the problem is: - mineral.