If you are buying a colored diamond you should make sure if it is color treated or colored from nature. Promise rings are less formal than wedding and engagement rings and are usually less expensive. Titanium promise rings are more reasonably priced than gold and silver promise rings.
Diamond Certificate
Explanation of Cut, Color and Clarity of This Diamond
Cut Quality The ideal cut diamond is a very precise mathematical equation, where diamond proportions and angles are cut to optimize the diamond's superlative optical properties, in particular it's high refractive index and color dispersion, to create a diamond of unequaled beauty with perfect balance of brilliance and fire. In layman's terms, the diamond is cut to make it the most beautiful diamond so it retains its intrinsic value.
Color Color grade I is in the middle of the near colorless category. Typically a trained professional will be able to discern the presence of color. Some people prefer warmer colors like I. When I color diamond is set in yellow gold jewelry used with yellow gold bezel, the diamond will appear as gorgeous as any of the higher graded stones.
Clarity Diamonds of SI3 clarity are on a borderline between slightly included and included diamonds. SI3 grade inclusions are almost obvious under 10x magnification. Inclusions in such diamonds may be noticeable to the unaided eye. However, when observing the diamond "face up" as it is mounted in a ring, the inclusions are usually not visible.