What Is a Mineral?

Amethyst crystals from Brazil Click on image for full size (20K JPG) Courtesy of Corel Photography

Minerals are the building blocks of rocks. They are non-living, solid, and, like all matter, are made of atoms of elements. There are many different types of minerals and each type is made of particular groups of atoms. The atoms are arranged in a network called a crystal lattice. The lattice of atoms is what gives a mineral its crystal shape.

Different types of minerals have different crystal shapes. Most minerals can grow into crystal shapes if they have enough space as they grow. But there are often so many different crystals growing in the same little area that they all compete for space and none of the crystals is able to grow very large.

There are two main ways that new crystals of minerals grow. Some minerals form when molten rock, called magma below a planet’s surface and lava above, cools and atoms bond together into mineral crystals. Other minerals form when water that has atoms of dissolved elements in it, evaporates away. The atoms get very close to each other and may bond together to form solid minerals.

The special shapes of minerals are not the only difference between them. Minerals can be identified by other physical properties as well. Each type of mineral has its own special characteristics.