There are many similar synthetic worktops going under different trade names, but most of them use the acrylic resin polymethyl methacrylate with a mineral filler, usually aluminium trihydrate, (derived from bauxite, which is aluminium ore). Colour (and a couple of other additives) finally make up the material. These are what Getacore admits to using.
The Corian-type materials were invented by DuPont, who use the same resin as above, but who won't say what their filler is. It's likely to be just the same stuff as the others use.