Coming across Rt. 30 in PA, I visited a regular honey hole (David knows where!). Here I picked up another stone ($.50). It is about 1-1/4" X 5 to 6" long. The top appeared to be a natural black stone, the bottom, at first I thought was leather bonded to the stone, because it felt like stiff leather.
A bit ago, I began cleaning some items and this stone was one of them. In straightening out what I thought was the black section, turned out to be purple, fairly hard and maybe just a bit softer than a washita. It is a natural stone, mainly because of the irregularity on the sides and bottom. The bottom is a stone, though it appears to be man-made because it is so well molded onto the top section. When cleaning, it comes out a light tan.
My question is concerning the purple part of the stone: any guesses as to what it might be? I believe the stone was used for knife sharpening because of the wear.
And David, no other bargains, though there must be nearly a hundred saws in the $3.00 pile.