diameter of the ring is 17.8 mm and its changable according to your order.theres 7 gems with princess cut ; one with 2.5 mm sides, two with 2 mm sides and 4 with 1.5 mm sides.the whole weight is 5.47 gr 18 kw.my linkedin profile: http://www.linkedin.com/in/forough-peivandi-502266303