Photos and information about 80 common rock-forming, ore and gemstone minerals from around the world.

There are approximately 4000 different minerals, and each of those minerals has a unique set of physical properties. These include: color, streak, hardness, luster, diaphaneity, specific gravity, …

Most of Earth’s crust is comprised of a small number of minerals. These minerals are known as the common rock-forming minerals.

Fluorescent Minerals Fluorescent Minerals and rocks glow with spectacular colors under ultraviolet light.

A list of minerals in order of hardness can be a handy reference. If you determine that a specimen has a hardness of Mohs 4, you can quickly get a list of potential minerals.

An introduction to rocks and minerals with detailed photos, description and identification information. Sponsored by the National Audubon Society, the National Wildlife Federation, and the Roger Tory …

The best way to learn about minerals is to study with a collection of small specimens that you can handle, examine, and observe their properties. Inexpensive mineral collections are available in the …

A small number of minerals and rocks will glow with spectacular colors under ultraviolet light. Learn how this happens.

The best way to learn about minerals is to study with a collection of small specimens that you can handle, examine, and observe their properties. Inexpensive mineral collections are available in the …

Southern California is one of the most important areas in the world for the production of gem-quality and specimen-quality tourmaline. Numerous mines over the past 100 years have also produced …