all the stones you have there are good for knives
Printable View
all the stones you have there are good for knives
On the last picture could be possibly natural. Can yu degrease it, lap it and make more pictures?
So, how can you tell what kind of stone it is. Are the finer quality stone marked? I have several very very smooth stones, especially the one that looks natural (The Last Picture) and the other two dark one also. The One Mitteilein or Mittellein I can find no info on (I am pretty sure its from Germany) It is more on the course side of things. Do the boxes help tell the age of a stone?
Personal experience, knowledge and often recognised sample to compare with.
the combo looks like a Norton, Not sure about the others...