Use a bail to hang a gemstone or pendant - available in pinch style, where the 'teeth' of the bail goes through a hole in the bead, or glue on bails, for when you're using an undrilled stone. 
bail (also spelled "bale") is a component of certain types of jewellery, mostly necklaces, that is used to attach a pendant or stone. The bail is normally placed in the center of the necklace where the pendant hangs. Some bails are made so a pendant can be attached after the necklace production is completed.