Chalcedony is a good idea if you can find enough material for the
drops that are white enough. Since you have already mentioned MOP, I
assume the customer is unconcerned about low end cost, therefor you
could do a bright white marble. This is a relatively cheap material
(especially for jewelry purposes), and it cuts and polishes very
easily. I have some football shaped beads that are very bright white
that you could grind and polish to shape, but the hole goes all the
way through. If you can show your customer that a pin through the
drop is almost the same look (and safer cause no glue), I’ll send you
a dozen no charge. You will have to grind them yourself because I
don’t have the time right now, and having me custom make them would
be cost prohibitive. If you can do your own minor lapidary work, you
will know that marble is a breeze, or maybe you have a local lapidary
friend. Send me your mailing address offline, the mailing cost should
be cheap enough I can cover it. Thomas III