You have mentioned that you cannot trace any prongs to hold the
stone? Well, it may be the case that it is held with a gold wire
spring which has been pushed in a groove which has been laid across
the bezel under the stone. It’s my preferred type of setting instead
of those flimsy prongs, as it is really nice and holds very neatly
the stones in a bezel setting. One has to be very accurate to do
this kind of setting otherwise the wire spring would not clip in the
groove with the result that the stone might fall. Hope this helps to
answer your query! JOSEPH TANTI, MALTA - EUROPE
http://jostanti.cjb.net