The shank features a high polish finish. We use high quality Cubic Zirconia Simulated Diamonds in our jewelry. Cubic Zirconia, or CZ, is a stone so optically close to diamond that most jewelers cannot tell the difference between a CZ and a diamond with the naked eye.It resembles the same optical characteristics, radiance and beauty as diamonds. CZ is much less expensive than diamond, optically flawless, and can be created in a variety of different colors. The biggest difference is that CZ is 70% heavier than diamond.