A mineral is a naturally occurring, inorganic element or compound with a definite chemical composition, a characteristic crystalline structure, and distinct chemical properties.The study of minerals is called mineralogy.

It includes mineral identification and description, the classification of mineral groups, and the study of mineral occurrences.

Minerals - A to Z      Minerals By Color

Gems are substances that have economic and aesthetic value. Most gems are minerals. However; some gems are organic substances such as amber, while others are rocks. Professionals who specialize in the study of gems are called gemologists.