London-listed Petra Diamonds has launched a special tender process for its Letlapa Tala Collection, which comprises five blue diamonds of significant colour, clarity, size and heritage.
The diamonds were recovered from the company’s Cullinan mine, in Gauteng.
The sales tender for the collection will close on November 24, following viewings in the key diamond centres of Antwerp, Hong Kong and New York during November.
Letlapa Tala means “blue rock” in Northern Sotho, also known as Pedi, which is the predominant language spoken in the Cullinan area.
The five Type IIb blue diamonds in the collection range from 6.61 ct in size to 25.75 ct in size.
Petra explains in a release that Type II diamonds contain no detectable nitrogen in their chemical structure and tend to display exceptional transparency. Type IIb diamonds contain a small amount of boron, giving the diamonds their blue colour.
The company adds that blue diamonds are so rare that most people working in the diamond industry have never even seen one. There are no official statistics on their recovery, so it is even more unusual that these five diamonds were all recovered within the space of one week’s production in September.
The Cullinan mine is known as the world’s most important source of blue diamonds, as well as being the source of many other historic and magnificent stones, including the 3 106 ct Cullinan diamond, which was cut to form the 530 ct Great Star of Africa and the 317 ct Second Star of Africa, being the two largest diamonds in the British Crown Jewels.
Petra notes the likelihood of it being the first time that five blue rough diamonds have ever been offered for sale at one time, with buyers being offered the chance to bid either on individual diamonds, on more than one, or for the entire collection.