Solid Kinds of solids Minerals
 Minerals are natural solids formed through many geological processes under high pressures. To be thought as a true mineral, a substance must have a crystal structure with uniform physical things throughout. Minerals differ in composition from pure elements and simple salts to very complex silicates with thousands of known forms. Some minerals, like quartz, mica or feldspar are common, while others have been found in only a few places in the world.