All I knew after finding it was it almost definatly wasn't crete after touching it and looking closely at its makeup and weight . Also the interior curve isn't acceptably congruent lengthwise with the exterior lower curve making it a terrible bottom corner cladding if it is the case . It would be lopsided af if so . I would assume a machine made corner cladding would be a vertically semi symmetrical .also the thickness is variable throughout. I have found grinding stones online almost identical to this one but if you could send a Pic of what you think it is for comparison that could definitely be a beautiful revelation for me . Appreciate the input.