Mineral

A mineral is a naturally occurring, inorganic, homogeneous solid, such as quartz, mica, or gypsum. Minerals are most commonly found as components of rocks, which are mixture of minerals, but are often found by themselves in more or less pure form.

The molecules of a mineral usually are arranged in a regular pattern, and may grow in a regular, visible, crystalline structure. When they do, they are often beautiful in appearance.

Minerals whose appearance and other characteristics (such as hardness and durability) make them suitable for jewellry or decoration, are known as gems or as semiprecious stones.

The commonest minerals found in rocks are quartz, feldspar, and muscovite (mica).