When choosing a colored diamond, there is a lot to consider, from the color itself to whether it has been treated or natural. You also have to consider supply and demand. When it comes to pink diamonds, they are considered one of the rarest and highly sought after diamonds, especially since they are used in engagement rings. This makes them an emotional purchase. Pink diamonds are also used in other settings such as earrings and necklaces, but they do not have the same impact as a pink diamond engagement ring . Diamond classification by the GIA In white or colorless diamonds, the GIA or Gemological Institute of America, grades that is based on the carat, cut, clarity and color of the diamond. For colored diamonds, they base their prices on the depth of the color. An elegant pink diamond will cost less than a vivid pink one. While there is no formula to determine how much more it would cost, the intensity of the color is the most important factor in determining the value of colore