This rock was picked up this summer at High Rock in Keeweenaw Co. MI. I'm sure it's basalt, but is odd the aggregate when chipped is tan to white inside and contain a lot of tiny crystals. The reddish brown seems to be a coating holding it all together.A cut ground and polished image was added.
closed as off-topic by user12525, Erik, uhoh, Fred, Peter Jansson Sep 4 at 11:27
This question appears to be off-topic. The users who voted to close gave this specific reason:
- "Questions about rock identification requests are off-topic. For more information, see the announcement on meta." – Community, Erik, uhoh, Fred, Peter Jansson