i acquired this hone from an old friend of my grand mothers while cleaning out his home after he died many years ago. i have no idea why, but tonight i picked it up (never used it before) to finish off the edge on my kershaw knife and just got the feeling there was something special about it. can anyone tell me anything about it at all? i found one on ebay selling for $99, identical in every way, but the ebay one has some chips in it but it has the box.

the only markings on it are what you see on the top of it, but it is incredibly smooth.