This formation contains most of the world's reserves of minerals such as andalusite, chromium, fluorspar, platinum and vanadium.
en.wikipedia.org A subgroup is the andalusite, staurolite, kyanite and sillimanite-schists which usually make their appearance in the vicinity of gneissose granites, and have presumably been affected by contact metamorphism.
en.wikipedia.org These minerals, known as index minerals, include sillimanite, kyanite, staurolite, andalusite, and some garnet.
en.wikipedia.org The accompanying amphibolite facies metamorphism is characterized by sillimanite and, locally, garnet, andalusite, and cordierite.
en.wikipedia.org The metamorphic grades of aureoles are andalusite hornfels, sillimanite hornfels, pyroxene hornfels.
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