Hi Charlie,
Corian is the brand name for a solid surface counter top material made by Dupont. It comes in different colors and designs. I use the Glacier White as it is a solid white material. Apparently there are other similar products that works just as well - candlestone is one that I have seen referred to when researching Lithophanes. It cuts easily - I have used both 60 deg and 30 deg v-bits. I use a parallel carving operation at a 45 deg orientation with 0.0075 step over. With the 45 orientation I don't do a roughing pass. Doesn't make chips with that small of a step over but so far it has worked for me.
Doug