Geology: Mineralogy & Petrology

This site, provided by the Mineralogical Society of America, is designed to be used online to identify mineral specimens. It guides the user through the process of performing simple diagnostic tests to identify possible matches; once a match is identified, other resources, including print mineral identification guides, can be used to confirm the identity of the specimen.

This site is an interactive reference guide to minerals and gemstones. It contains information on minerals (organized alphabetically, by chemistry, crystal structure, color, streak and hardness), gemstones (organized alphabetically, by color and crystal group), a photo gallery, glossary and links to additional resources.

The Mineralogy Database contains information on more than 4000 minerals and images of more than 3700 specimens. Information on minerals can be accessed through an alphabetical list, by crystal form, chemical composition, mineral property, or other means.

Mindat.org, which bills itself as the "largest mineral database and mineralogy reference web site on the Internet," contains information about minerals of the world, mineral collecting and localities, and other resources, including a directory of dealers, clubs, shows and web sites. Minerals can be searched by name, property, chemistry and association (when two or more minerals occur together in the same deposit).

The American Mineralogist Crystal Structure Database is a free index to crystal structures (the arrangement of atoms or molecules in a mineral) that were published in the journals American Mineralogist, Canadian Mineralogist, European Journal of Mineralogy and Physics and Chemistry of Minerals. It was developed at the University of Arizona by Robert T. Downs and Michelle Hall-Wallace. The database provides crystal structure data that can be used in software, as well as citations to articles containing the data.

RRUFF is a cooperatively developed, openly accessible collection of Raman spectra for minerals.

GeoRoc is a database that contains information on geochemical analyses of volcanic rocks and mantle xenoliths (rock fragments of the mantle that are found as inclusions in other rocks). It contains analytical data on over 275,000 rock samples, including sample location, rock name and type, age, and chemical composition, as well as a citation to the article containing the data.

The Rock Identification Key, from the Mineralogical Society of America, provides information on rocks and a guide to identifying rock specimens. It provides basic information about rocks, types of rocks, the rock cycle, rock-forming minerals and rock collecting. It also contains information on common rocks, including the type of rock, appearance, mineral composition and how each type of rock forms.