Actually those stones into stones are usually drilled holes with
metal bezels around the top stone and set on base, then inserted
through the drilled hole in the base stone with a rivet, which when
finished and set - the rivet is not seen! Now are you totally
confused? Glue is not necessary except on the back of the "larger"
back stone to help secure the rivet! I don’t know what experience
you have with drilling, but that could require a bit of instruction
Rose Marie Christison