Online publication with brief descriptions of most types of terrestrial and lunar igneous rocks, their regional distribution and classification, and examples of their geochemical trends and "fingerprints".

Information on granite and its forms, and an exploration of the granite origin controversy written with a minimum of technical jargon.

Page with links to course summaries for Petrology and Petrography, and related coursework.

Offers a variety of analytical services related to obsidian trace element characterization ("sourcing") studies, obsidian hydration studies, and obsidian source studies, primarily in the context of archaeological research.

Information on the mineralogy and petrology of pegmatites including an online publication and links to pegmatite-related sites.

This site is devoted to granite petrology with an emphasis on the Llano Uplift granites of central Texas. Also includes links to research, meetings and other scientists.

Describes the geology, petrology and geochemistry of the Northbrae and Leona Rhyolites in the East Bay Hills, San Francisco Bay Area, California.