I bought this stone off ebay; it was nearly black with oil and dirt, but cleaned up nicely. Very hard and smooth, it dished my Norton lapping stone a bit. It appears to be a natural stone and was labeled only "GERMANY". Color is light yellow with darker tan inclusions. Any ideas? It's not novaculite nor do I believe it is a coticule. PAttachment 97430Please excuse the poor photo; I haven't posted photos in a while and I am very rusty