Chlorastrolite | Article about chlorastrolite by The Free Dictionary
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A mottled, green variety of pumpellyite occurring as grains or small nodules of a stellate structure in basic igneous rock in the Lake Superior region; used as a semiprecious stone.
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He attended the Michigan College of Mining and Technology (now Michigan Technological University), where he completed a Bachelor of Science program in Geology and a Master of Science program in Mineralogy (1957) with a thesis titled "A Study of Chlorastrolite
, also known as Isle Royale greenstone, was designated as the official state gem.