what is a mineral

A mineral is a naturally occurring inorganic solid with a definite chemical composition and an ordered atomic arrangement. Minerals are the building blocks that make up rocks. They can be identified by several physical properties such as hardness, lustre, streak, and cleavage. Some common minerals include quartz, feldspar, mica, amphibole, olivine, and calcite. A rock is an aggregate of one or more minerals, or a body of undifferentiated material. The geological definition of a mineral normally excludes compounds that occur only in living organisms. However, some minerals are often biogenic, such as calcite, or organic compounds in the sense of chemistry, such as mellite.