Half moonstones have a straight edge on one side, and a curved one on the other.         These look wonderful with rectangular centerpiece gemstones shaped in the princess cut, radiant cut, or emerald cut since each of those has a straight side. Owing to the rounded edge, they work well with oval-shaped gemstones as well. That means you have lots of accent stone options when shopping for a half-moon diamond ring. With the cushion cut’s reemergence in the gem and jewelry market lately, half-moon diamonds have become an extremely popular option for side stones on cushion-shaped diamond rings. Early gemstone cutters used to shape half-moon diamonds from broken oval and round-shaped ones. The challenge for them was not just cutting the gemstones to exact proportions, but also finding broken gems with the exact color that they could work with. Nowadays, the demand for half-moon diamonds necessitates that craftsmen cut big numbers in several different shapes, sizes, and colors. Then, sorters find matched pairs kept together to be sold in the market as side stones.