if you have a jewellers handpiece you can use these ones best to shape the pearl
http://www.ebay.com/itm/NEW-LOT-OF-...ultDomain_0&hash=item2570cc4cd8#ht_500wt_1204
they use them to make porcelain teeth etc there way thinner than the normal ones you can buy for jewellers and stone carving because of this you can work nicer and more precise
then to finish them you can use
http://www.ebay.com/itm/DENTAL-COMP...ltDomain_0&hash=item20c5933f2f#ht_3264wt_1189
also easy to ask a dental lab if they have some old ones they most of the times have so no need to pay much for them
you do need a flexshaft for these pieces or a cheaper proxxon micromotor or more expensive micromotor, and nsk water motor
you can find them on ebay a lot and there also nice for drilling pearls
http://www.ebay.com/itm/Jewelers-To...ultDomain_0&hash=item4d0198a6cb#ht_500wt_1204
just make sure when you buy the discs that they fit in a 2,35 shaft
the reason i use dental ones i because jeweller ones are most of the time harder as they are made for metal and not porcelain like structure
i know a lot of people here have these tools but for those who don't buy them its fun to do and nice to always have tools to drill pearls