Many very large and famous yellow and orange diamonds have been unearthed and sold for strong prices at auction. One of the largest yellow diamonds is the 407.48 ct Fancy Deep brownish yellow (and Internally Flawless) Incomparable diamond, discovered in the Congo. Other famous yellow diamonds include the 128.54 ct Tiffany Yellow (South Africa), the 132.27 ct Florentine (India), the 127 ct Sun of Africa (South Africa), the 101.29 ct Allnatt (likely South Africa), the 30.54 ct Arctic Sun (Canada), and the 4.25 ct Kahn Canary (Arkansas, United States).
Orange diamonds are considerably rarer than yellows, particularly unmodified pure orange hues, but a few famous ones exist. The largest is The Orange, a Fancy Vivid orange diamond of unknown origin weighing 14.82 ct that sold at auction in 2013 for ~US$2.4 million per carat, a record price at the time. Another well-known orange diamond is the Pumpkin, a 5.54 ct Fancy Vivid orange stone from the Central African Republic purchased the day before Halloween in 1997 for US$1.3 million.
Natural yellow gem diamonds are the most common of the fancy-color diamonds, while orange diamonds are among the rarest when they have unmodified hues. Both categories owe their coloration to atomic-level lattice defects associated with nitrogen impurities in the diamond structure.
Yellow and orange diamonds owe their color primarily to nitrogen impurities that are incorporated in the diamond lattice during growth deep in the earth. Nitrogen is the most common impurity in natural diamond due to the very similar atomic radii of nitrogen and carbon atoms
With time at high temperatures deep in the earth, the nitrogen atoms in most diamonds aggregate, resulting in either near-colorless stones or yellow diamonds colored by cape defects. Yellow and orange diamonds can be grown in a laboratory or created by color treatments, so a thorough understanding of the defects responsible for color in the natural stones is critical for identification. Yellow diamonds serve as the best ambassador to the colored diamond world due to their abundance and may be the only colored diamond many people will ever see in a jewelry store.
Comments