Thread: eny idia wat this mite be

i found this at a boot sale if was in with a loud of tools,it is grayish/orange very well worn one side i´ve laped the other side with 320 grit sandpaper its very smooth seems very fine and hard sucks water like crazy for 25 mins slurry is milky a bit likt coti .. ent idias please b4 i put a razor near it ....