The Big Diamond : The Darya-I-Nur Diamond is one of the world's largest diamonds and is one of the most rare because of its pale pink color. It weighs about 182 carats (36.4 g). Its exact weight is unknown because its been mounted in its brooch setting for over 130 years. Its Persian name 'Darya-I-Nur' translates into English as the 'Sea of Light'.Diamonds that enter the Gemological Institute of America's scale are valued according to their clarity and color. For example, a "D" or "E" rated diamond (both grades are considered colorless) is much more valuable than an "R" or "Y" rated diamond (light yellow or brown). This is due to two effects: high-color diamonds are rarer, limiting supply; and the bright white appearance of high-color diamonds is more desired by consumers, increasing demand. Poor color is usually not enough to eliminate the use of diamond as a gemstone: If other gemological characteristics of a stone are good, a low-color diamond can remain more valuable as a gem diamond than an industrial-use diamond, and can see use in diamond jewelry.
Diamonds that go out of scale in the rating are known as "fancy color" diamonds. Any light shade of diamond other than light yellow or light brown automatically falls out of the scale. For instance, a pale blue diamond won't get a "G" or "K" color grade, it will get a Faint Blue or Light Blue grade. These diamonds are valued using different criteria than those used for regular diamonds. When the color is rare, the more intensely colored a diamond is, the more valuable it becomes. Another factor that affect the value of Fancy-Colored diamonds is fashion trends, Pink diamond fetched higher prices after celebrity Jennifer Lopez was photographed wearing a square shaped pink diamond.
Fancy-colored diamonds such as the deep blue Hope Diamond are among the most valuable and sought-after diamonds in the world. In 2009 a 7 carat blue diamond fetched the highest price per-carat ever paid for a diamond when it was sold at auction for 10.5 million Swiss francs (US$9.5 million at the time) which is in excess of US$1.3 million per carat.
The Aurora Diamond Collection of natural color diamonds is one of the most comprehensive diamond collections in the world.
