‐-----------------------‐-update 11-11‐----------------------
After more research and some lucky talks I believe this to be epidote from tailings out of the Wolverine Mine, a few miles from where I found these pieces.
‐-----------------------‐-original post------------------------
Was rock hounding on the southern shore of Lake Superior. Found these green crystal deposits that formed like geodes, specimens are small, the largest is about the size of a corn kernel. A local said it could be chlorasolite but I don’t think it matches based on color and clarity. Any thoughts would be appreciated!
Found it in gravel that likely came from copper tailings if that helps.
Copper tailings, you say? It could be a sulfate precipitate of some kind. Probably a mixture of anything and everything, with lots of iron in it. If so, the crystals would be more or less water soluble. If so, you really need to skip the lick test.
Iron sulfate is usually nice and green, but contaminants tend to alter the color. Also, there are other green sulfate compounds, so narrowing it down without XRF can be tricky.