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Datolite crystals are imbedded in greenstone--talk about unusual! Half of this cabochon is datolite and half is greenstone. I have found less than a dozen of these in my lifetime, this stone is grade A all the way around for somebody who wants something really really different! .7 grams
The greenstone, also known as chlorastrolite, is the state gem of Michigan and is found only is small select areas of the Keweenaw Peninsula or on Isle Royale National Park.