November Speaker: A Very Close Look at Rodingite from the Hunting Hill Quarry, MD by Tim Rose

by Cindy Schmidtlein, MSDC Vice President

Our speaker for the November meeting will be Tim Rose, Laboratories Manager in the Department of Mineral Sciences at the Smithsonian. Tim has worked for the Department of Mineral Sciences since 1979 and has been the manager of the analytical labs in Mineral Sciences for over ten years. In 1991, he completed a Master of Science degree at the University of Maryland where he studied the Phillips pluton in Maine. At the Smithsonian, Tim's research and publications have included Kilauea volcano's explosive history as well as a host of other interesting topics.  

Tim's talk will provide a close look at rodingite, a beautiful rock from the Hunting Hill Quarry, Maryland. Having collected specimens of rodingite in his youth, Tim was able to visit the Hunting Hill quarry many times with others from local clubs in the 1980s. Quite a few minerals can be found there including beautiful gemmy cinnamon-colored grossular garnets associated with open cavities in rodingite. Besides the garnet, this coarse-grained rock contains beautiful green crystals that everyone knows are chromian (chromium-bearing) diopside. But wait, who said and where’s the evidence?  Tim's presentation will allow us all to take a closer look at this pretty green mineral that has a cool flash when light reflects off of it.