Amen to what Wayne has said. To elaborate a bit, EVERY stone surface that
is intended to be polished has to go through all the stages of what Don
Depue from Diamond Pacific referred to as "the lapidary process". That's a
useful term. It applies whether you are carving, cutting a cabochon, or
facet-cutting. In a standard round brilliant there are 57 individual
surfaces that ALL go through the stages:
First, there's rough cutting. That's done with a coarse aggressive grit
which removes a lot of material fast. This leaves deep scratches and is not
remarkably accurate. So it's followed by...
Stage 2, fine cutting with a fine grit abrasive. This takes out the coarse
scratches from the previous stage and leaves a finer and more precise
surface but one that is still too rough to take a polish. This is followed
in turn by...
Stage 3, surface conditioning - or pre-conditioning with a very fine
abrasive, often also known as "sanding" or "pre-polish." Leaves a fine
precise surface; sometimes it is possible to go directly to polish from a
one-stage surface conditioning, usually this is followed by a still finer
Stage 4 - polish.
In all cases the usual trade-off applies - you can do it faster, but not
accurately; you can do it accurately, but not fast. And that's just the
mechanics of the process. It doesn't take into account the fact that
different stones behave quite differently, different speeds have differing
effects, different abrasives and polishing agents work better for some
stones than for others, and a whole host of similar variables that take
years of experience to anticipate.