Minerals are solids – not gases or liquids. They are inorganic, so they are not made by or come from living organisms. Minerals are made by nature, not by human hands. They haven’t been made by scientists in a laboratory, for example.
Which of these pictures is a mineral? Why? 

Minerals share a special chemical composition. Like a recipe, it is a unique combination of atoms that has to be perfect to grow a specific mineral.

Minerals almost always form as crystals. A crystal is a solid with atoms arranged in a three-dimensional pattern called a crystal structure. 

Mineralogy is the study of the chemistry, crystal structure, and physical properties of minerals and how they are formed.

A person who studies mineralogy is called a mineralogist. This mineralogist is Mr. Richard T. Liddicoat, the “Father of Modern Gemology.”