Ron, Corian is a polymer made by DuPont. It is actually a plastic matrix with minerals such as alumina or bauxite embedded. It is very heat resistant BUT it will scorch or discolor, even melt if the heat is high enough. Ok for warm dishes and so on, not recommended for hot pans right off the stove. Though I know many people who do that and mostly it works OK.
The counter in our bathroom at the house is Corian. The previous owners left a candle or something hot burning on it and you can see the ring if you look at it at an angle. Still good stuff for most applications.