It's an abalone laminate, with thin Micarta on the back, and a clear acrylic over the top. Pretty neat stuff, and very stable.
As far as selling, these took me 3 hours to make and the material is expensive. If you got the money, I got the time! The little grips are very difficult to hold when making. Things like 1911 grips would be much easier, but use more material.
Thanks, everybody!