Petra Diamonds Ltd. announced a special tender process for the five blue diamonds of significant colour, clarity, size and heritage sourced from the Cullinan Mine in South Africa. The diamond quintet has been named the Letlapa Tala Collection.
Letlapa Tala means ‘blue rock’ in Northern Sotho (commonly known as Pedi), the predominant language spoken in the Cullinan area.
The Letlapa Tala Collection consists of five Type IIb blue diamonds of 25.75, 21.25, 17.57, 11.42 and 9.61 carats in size. Type II diamonds contain no detectable nitrogen in their chemical structure and tend to display exceptional transparency. Type IIb stones contain a small amount of boron which is what determines their blue colour.
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 therefore even more unusual that these five spectacular stones were all recovered within the space of one week’s production in September 2020.
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-carat Cullinan diamond which was cut to form the 530-carat Great Star of Africa and the 317-carat Second Star of Africa, being the two largest diamonds in the British Crown Jewels.
The unique geology of the Cullinan kimberlite pipe means that the majority of its diamonds are aged between 3.2 and 1.1 billion years old – spanning a time in the Earth’s history from before the formation of the first major continents to the beginnings of multicellular life. However, Type IIb blue diamonds are so rare that their age has not been established.
This is likely to be 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 stones, more than one, or for the entire collection.
Caption: The diamonds have collectively been named the Letlapa Tala (meaning ‘blue rock’) Collection.