This series of 4 x 6 mm stone rings comes in 1, 2, 3, 4, 5, 6, 7 and 8 Stone versions. They weigh about 4 grams in sterling and about 5.1 grams in 14kt gold. The stock ring size is about 7 and can of course be sized to any size you need.
W4014, W4015, W4016, W4017, W4018, W4019, W4020, W4021