This reef knot ring is hand formed from 16 gauge (1.29mm) sterling silver wire. The stone in the center is a 6mm round black star diopside. This stone is a little unique as each is cut to display a 4 ray star when rotated. Each ring is hand formed not cast so yours may vary slightly from the picture.
Please note that the last two images show a similar ring set with labradorite. These images are here to give you an idea of what the side and back of the ring look like, and to show some of the possible varriation between rings..