Corundum
General Description
Corundum is the aluminum oxide that gives us such gems as ruby and sapphire in its very rare and purest crystalline forms. Lapidaries will recognize this ruby-fuchsite association (sometimes called "watermelon ruby") as a popular ornamental material available on the internet from India and other locales. Click on above images for captions.
History
None listed for Central Wyoming
Uses
Lapidary and display
Abundance
Limited locations in Fremont County and a few other places in Central Wyoming.
Quality
Various qualities, but few are gem grade.
Location/Restrictions
It is reported from a few locations in Fremont County, notably in metamorphic outcrops above Beaver Rim. There are a couple of ruby claims in the Stampede Meadows area, but it is doubtful whether gem-grade material was ever recovered from them. Corundum with a pale blue cast, i.e., “sapphire,” has been found at a location a few miles from Sweetwater Station where there is an old prospect hole, but it is far from being gem grade. Both of these corundum occurrences are found in a greenish schist, in which the corundum is embedded as nodules. The reddish-violet “rubies” are typically surrounded by a rim of bright green fuchsite, a micaceous mineral which might be a main constituent of the schist itself.
Publications/Links
Gemstones and Other Unique Minerals and Rocks of Wyoming
Consult Hausel and Sutherland, Gemstones and Other Unique Minerals and Rocks of Wyoming, for more information.
Publication 2
more to come
Publication 3
more to come