Natural fancy purple diamonds generally are worth more per carat than most other diamonds in the fancy color range. Common descriptors for such stones include orchid, plum, lilac, mauve, lavender and grape. They can be split into two categories, with the more variety being violet diamonds, which are close to blue-grey on the color spectrum. The rarer stones are purple, with most having pink or red secondary colors. Purple diamonds with no secondary color modifiers are the rarest of them all. The source of the color in purple diamonds are trace elements that include nitrogen, boron, and most importantly hydrogen.