I set this botswana agate in a bezel of 18k gold, atop a baseplate of 22k gold/silver bimetal. This bimetal is the result of fusing of 22k gold on top and argentium sterling silver below. The layer of gold comprises 10% of the metal, thereby offering far more gold than gold filled and vermeil--yet making the look of 22k gold far more affordable. I framed the lower edge of the stone with a lush fringe of freshwater pearls on 18k gold headpins. The chain is oxidized silver with a cluster of 18k gold sprouts to one side. The necklace adjusts from 18 to 20 inches.