After enlarging the hole in the raw lapis lazuli I put a meter long 1mm sterling silver wire through, I then flatten the wire on both sides of the stone before wrapping it.
I attach oxidized sterling silver chain to each side of the stone with copper hoop and add a handmade copper s-lock, I give both the lock and the copper around the stone a rustic antiqued finish by oxidizing and brushing it.
Since the stones are natural they are a bit irregular in shape but they measure approx 35-40mm. including the wire wrap. The chain measure 170mm on each side of the stone and the lock approx. 20mm.