About Isle Royale Greenstones


Isle Royale Greenstone (Chlorastrolite) is the official state gem of Michigan. It is a variety of the mineral pumpellyite and is found chiefly as a small, green, rounded beach pebble, showing a turtleback pattern. Greenstones can still be found on Isle Royale and on some of the mine waste piles of the Copper Country, although it is a rare mineral.