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, …

What Are Rock-Forming Minerals? Scientists have identified over 4,000 different minerals. A small group of these minerals make up almost 90% of the rocks of Earth’s crust. These minerals are known as …

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

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

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 …

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 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.

Information on over 500 minerals, complete with detailed color photographs, crystallographic diagrams, physical and chemical properties, and much more. More information, table of contents.

Amphibolite is a coarse-grained metamorphic rock that is composed mainly of green, brown, or black amphibole minerals and plagioclase feldspar. The amphiboles are usually members of the …