What is the rarest diamond in the world?

Answer 1

Rarity can be based on a couple of things -- mainly, color and carat weight. Diamonds come in almost all colors: red, pink, yellow, champagne, white, green, blue, brown and black. The availability to obtain a specific color is what determines rarity as well as the uncut and cut size of the diamond.

The rarest diamond in the world based on color is The Ocean Dream Diamond weighing in at only 5.51 carats, but the color is one of a kind: blue-green.

The rarest diamond in the world based on size is The Cullinan Diamond originally weighing in at 3106.75 carats. That gem was then cut in nine large chunks, 96 small ones and 9.5 carats of unpolished pieces and put into the various British Crown jewels. The Cullinan is white in color.

Other rare diamonds include:

• The Earth Star (248.9 carats, reddish-brown in color)
• The Blue Heart (30.82 carats, deep blue in color)
• The Centenary Diamond (599 carats, brilliant flawless white in color)
• The Golden Eye Diamond (originally 124.5 carats -- then cut and polished at 43.51 carats, flawless, Canary fancy yellow in color)
• The Koh-i-noor (Over 5000 year old gem weighing in at 108.93 carats after being cut down 80 carats, white in color)
• Spirit of de Grisogono (312.24 carats after it was cut down from 587 carats and now part of a ring containing 702 white diamonds, black in color)
• The Hope Diamond (115 carats to start with and then cut down to 67 carats and then finally weighing in at 45.52 carats and purportedly, carrying a curse, fancy deep blue in color)
• The Golden Jubilee (755.5 carats in the rough and 545.67 carats cut and polished, rich yellow brown in color)

Recent trends have led the industry toward fancy yellow, champagne, brown, pink and even a few red diamonds out there. The natural occurrence of these colours is rare, and some vendors treat stones so that they become these more rare colours. (Treated stones must always be documented as treated.)

Though white diamonds are generally thought to be the most common by consumers, the most common are brown and yellow diamonds that were discarded by diamond companies for years considering them to be "dirty" or "unattractive" in settings. Only now are people seeing the beauty in having a unique gemstone in even bridal settings and it's no uncommon to see a Canary yellow or a fancy blue on the left hand!