The Premier Blue

The Premier Blue is the largest round fancy vivid blue diamond to have been graded by the Gemological Institute of America, said Sotheby’s. It was sourced from the Premier (formerly known as Cullinan) mine near Pretoria, South Africa, the world’s main provider of blue diamonds.It is a brilliant-cut internally flawless stone, weighing 7.59 carats.

The pigmentation of blue diamonds is caused by the presence of boron atoms. The higher the concentration of that element, the deeper the color.“Fancy Vivid” is the grade with the highest saturation of color,

Colored stones, which account for about 0.01 percent of mined diamonds, dominate the top end of the jewelry market. Their scarcity and aesthetic appeal have triggered record auction prices in recent years, led by the 45.4 million Swiss francs ($45.6 million) paid by the London-based jeweler Graff for a 24.78-carat “Fancy Intense Pink” at Sotheby’s, Geneva, in November 2010.

The market for colored stones is strong because of their rarity.People buy them for investment purposes, and they can be seen as a hedge against what happens in other markets.

The Premier Blue is to be auctioned on Oct. 7 as part of  Sotheby’s 40th anniversary sales in Asia. This auction of jewels and jadeite in Hong Kong will comprise about 330 lots and is estimated to raise more than $HK600 million ($77.4 million).The Premier Blue is itself expected to sell for more than $19 million.