Colored by atomic-level defect arrangments, natural-color green diamonds are among the rarest gemstones found on Earth. The cover photo showcases diamonds that display a range of green hues. The diamonds in the rings (clockwise from top) are a 4.17 ct Fancy Vivid yellowish green, a 10.18 ct Fancy Intense yellow-green, and a 3.88 ct Fancy Vivid green, respectively. The unmounted diamonds in the top row are a 1.42 ct Fancy Vivid bluish green, a 1.01 ct Fancy Vivid yellowish green, and a 2.06 ct Fancy Vivid green-blue. In the bottom row are a 0.55 ct Fancy Vivid green and a 0.55 ct Fancy Vivid bluish green. Photo by Robert Weldon/GIA, courtesy of Optimum Diamonds.