grail
isle royale greenstone
Pumpellyite (chlorastrolite)
The tell
The turtleback. A mosaic of angular segments, each a slightly different green, and as you tilt it, the light moves ACROSS the segments, lighting some and skipping the one beside it. Epidote never does that.
Michigan's state gem. And the name is a trap: it is NOT collected on Isle Royale. The island is a national park and taking anything from it is illegal. Keweenaw beaches are where a legal one comes from.
What it gets mistaken for
- epidote
- thomsonite
- serpentine
- green agate
- chrome chalcedony
The facts
- also calledPumpellyite (chlorastrolite)
- age~1.1 billion yrs
- where it turns upKeweenaw beaches ยท NOT Isle Royale
- on the chartgrail · 100 stickers ever
Put it on the shelf
Every stone on this chart is drawn and kiss-cut at three inches. The rarer the stone, the fewer exist: only 100 isle royale greenstone will ever be printed, then the run is retired.
10% of every order goes to the Roscommon County Animal Shelter.