From the MAKE Flickr pool

Karl W. shares a pic of his newly acquired artifact

This ceramic wafer is a real mystery to me. I purchased it from a Ebay seller in Kfar Saba, Israel and during the shipment it cracked on the upper edge of it. It’s about 4″ x 4″ and just a bit thicker than a normal silicon wafer. I was thinking it could have been a early attempt at making small ICs, before silicon?
I’d love it if anyone could give me more information on what this is, it seems like quite a rare item from what I can tell.

A larger version of the image can be seen here.