Color-treated diamonds are a worthy substitute to white diamonds, especially considering their lower cost. A 3-carat pink diamond ring, for instance, would cost considerably less than a white diamond of the same weight and other characteristics. Following is a look at what to watch when buying a color treated stone.
Quality color treated diamonds are usually the products of either the HPHT process or irradiation. You should be wary of being fed the option of a color-coated diamond, which simply has a surface coating that can wear off quickly. People know this and are less likely to buy such a stone when you try to resell it. That brings down their value by several notches. Contrastingly, HPHT and irradiated color treated diamonds have been treated in laboratory settings to ensure they hold the color they have for much longer and even perpetually if you take care to keep them away from high temperatures.
As always, make sure to buy from a reputed jeweler, and to pick a stone certified by a reputed laboratory such as GIA. This certificate would have all the details you need about the treatment processes the stone has undergone.