I've been playing around with my vintage Thuri lately and wanted to figure out what color of Escher to compare it to. The stone is grey... SO I built up some slurry, wiped it off with my finger and smeared it on a piece of plain white paper. After drying i was left with a yellowish green smear. The stone has quite an earthy smell to it and after lapping with a dmt 325 it gets a noticeable sheen to the honing surface. The edges it's producing are buttery and smooth and nicely keen; not as keen as say my jnat but easily as smooth and with some practice probably smoother. I'll post pics of the stone and smear tonight with hopes of a Thuri buff piping up and telling me what I've got.

By no means am I trying to say this is an Escher but might be of similar quality.

Dimensions and pics to follow!