Great looking stone Tom. I have a La Dressante that has a spot that makes purpleish slurry but it doesn't hurt anything at all. I suspect the spots on your stone are manganese (hope so anyway). Very pretty stone congrats!
I agree^use the corner of a slurry stone and slurry just the spots one a time just a few to test. If the are a smoky blue they are manganese which i believe to be the case with at least most of them.
use the corner of a slurry stone and slurry just the spots one a time just a few to test. If the are a smoky blue they are manganese which i believe to be the case with at least most of them.
I look again I don't think there is any bbw present I think all are manganese deposits. Congrats on a beautiful stone!La cow layer. First paddle coti. Was sad that the spots I think are actually BBW running up through the top. When lapped slurry was purple. There is some pink in the coti though and it is very hard and fast on water only. Black after just a few laps as seen in pic.
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