There are a number of overseas (I mean from the US) and American cut
stone dealers who are very reputable. You should ask your friends who
they use and keep asking around, as prices do vary a lot, as does
quality (you know, color, carat weight, clarity, cut). Also attend
some gem shows and meet the dealers and get a sense of what they are
selling and how they behave. In the gem business it seems everybody
knows everybody else, and people who aren't on the up and up may be
able to exist for a very long time as bottom feeders preying on the
unwary, most everyone in the biz can tell you who they are --- there
are no secrets. Once you develop trust with a few good dealers and
other jewelers, they will help steer you to people you can trust.
If you seek the unusual, you should look under supplies at Etsy, as
there seem to be a lot of people selling various cabochons. There are
also some websites you can find if you google "designer cabochon"
which have some killer stones, but they are not necessarily cheap.
They are probably a good cut above the cheap Chinese material,
Let me put in a good word for the American, Canadian, British and
European custom faceters. I know a lot of them through the United
States Faceters Guild (USFG) discussion list at yahoogroups. Some of
these folks are hobbeists, some are part time pro faceters and just a
few are full time cutters. If you look around the internet you will
see some sites run by folks who only sell their own, custom faceted
stones. Some of these are old guys looking to sell a few stones and
some are high end cutters with custom designs and very expensive
stones. Virtually all of the hobby and pro cutters produce very fine
cut stones. The cutting tends to be several levels over what you
would buy commercially. Some of the facet designs are original and
many cutters optimize their designs for brightness and scintillation.
If you have customers who really appreciate quality, these are the
folks to look for. Some of them will cut to order, although sometimes
that depends on having the right rough on hand.
If you are looking for something in particular, you might try
putting a message on the USFG list to see who might have what you
need. There are about 1200 members and many are very, very good