September 13, 2010
6:00 - 7:30 pm
State Technical Community College
10915 Hardin Valley Road, Knoxville
Faculty/Staff dining room adjacent to the regular meeting room (Annex Cafeteria)
Graves Mountain, Georgia
A Brief Review of an Average Kyanite Mine And
World Class Mineral Collecting Locality
Travis A. Paris
Geologist, Aggregates USA, LLC
Graves Mountain is a small
monadnock rising above the Piedmont of eastern Georgia in western
Lincoln county Georgia. It is comprised mostly of
&ldquoquartzite&rdquo with significant localized
quantities of kyanite which were mined in the 1960-1990 period.
The mountain gained its notoriety not from the kyanite deposits themselves, but from the rutile crystals found mainly in the central part of the mountain. These were discovered in the mid 1850&rsquos by Dr. M.F. Stephenson and sent to Professor Charles Upham Shepard at Yale University, who published an article in 1859 on the complex twinning of the rutile and further distributed the samples. German crystallographers studied the crystals extensively and published a number of articles with detailed crystallographic drawings. Further exploration revealed the presence of the kyanite, pyrophyllite, and lustrous blue lazulite. Mining of the lazulite quartzite took place in the late 1800&rsquos, with material being cut into ornamental pieces and jewelry by Tiffany & Company. Collecting has continued through the years, with the identification of a suite of rare phosphate minerals in the early 1990&rsquos, as well as other minerals.
Graves Mountain is not &ldquounique&rdquo, but neither is it &ldquocommon&rdquo. It is part of a series of monadnocks extending northeast into Virginia. These monadnocks are all characterized by mineral assemblage of quartz+kyanite(+andalusite)+lazulite +pyrophyllite+pyrite+topaz and suites of rare phosphate and sulfate minerals.
The origin of the deposits has been and is being debated by numerous writers. Most ascribe the kyanite to regional metamorphism of aluminous sediments, some to regional metamorphism of altered volcanics, and a few to volcanic, epithermal processes. I subscribe to the epithermal theory and will briefly describe my views of the formation of the deposit.
Page updated September 13, 2010