I haven’t tried it, but it shouldn’t be impossible. It won’t be
easy, though. One problem is fixturing the stock; amber is difficult
to hold onto securely. I’ve had bad results with conventional
hot-dopping - the material doesn’t like to be heated, and it’s
difficult to get the wax off once it’s adhered. Gentler techniques
(no pre-heat, softer wax, warm water instead of freezing off) could
work, though. Materials are usually held down to the bed of a CNC
mill with clamps, but that would be a touchy procedure with amber,
which cracks easily. There’s usually not a lot of extra material to
hold onto either.
Another problem is the tendency of amber to chip as it’s being cut.
While it cuts cleanly (unlike copal, which tends to gum up) it’s hard
to get a chip to separate without a conchoidal fracture which can
extend farther than one might want. Add to that amber’s tendency to
accumulate an electrical charge and explode spontaneously if
over-charged, and one starts to appreciate the difficulty of the
As for the choice of machine; just about any commercially available
CNC mill would work, since sizes are small, and speeds don’t need to
be high. But if the shapes you’re cutting are simple convex shapes
like spheres, a standard (non CNC) cabochon preforming machine might
work just as well. These trace a master pattern mechanically, and
move a rough piece of stone into a grinding wheel to duplicate it. If
you wanted to reproduce a more complicated design, like a cameo or
intaglio, then I’d think CNC would be worth investing in.