I have some cheap synthetic facet cut stones, those facets are not
so good polished. The stones themselves are very clear, but the > >
reflected light is not bright.
The brightness of a faceted stone is more dependent on the angles &
arrangement the facets are cut at than the polish. That’s not to say
that the polish on the facets doesn’t affect the appearance of the
Unless you’ve got a very steady hand, you’ll probably have trouble
using a hand held flex shaft tool to improve the polish. It might be
possible to improve the polish on an isolated facet or 2, but over
all my guess is that you’d have problems.
Facet stones are best re-polished using a faceting machine. Even
then getting the stone properly aligned can be time consuming.