On August 10, Petra Diamonds announced that it had recovered a 138.57-carat, Type IIa, D-color diamond at the Cullinan mine in South Africa – the second large diamond to be recovered there in the space of two months. In June, the miner unearthed a 121.26-carat at Cullinan, also of “exceptional color and clarity,” as per the company.
The Cullinan, the oldest diamond pipe in the world, is one of the most famous mines in the world. Established in 1902 as Premier Mine, it was renamed the Cullinan Diamond Mine in November 2003 in celebration of its centenary. Today, Cullinan is owned by a three way partnership consortium: Petra Diamonds, Thembinkosi Mining Investments and Al Rajhi Holdings.
The first significant diamond to come from Cullinan, a 3106-carat rough stone, was unearthed there in 1905. It remains the largest diamond ever to be recovered at Cullinan, and the second largest in the world. It was named after the chairman of the mine, Thomas Cullinan, presented to King Edward VII of the United Kingdom for his 66th birthday, and then cut into several polished gems. The largest – Cullinan I or the Great Star of Africa – weighs 530.4 carats. Cullinan II weighs 317.4 carats. Both diamonds are exhibited at the Tower of London.
Cullinan is also a source of large, gem-quality blue diamonds. The mine has yielded the “Blue Moon of Josephine”, which sold for $48.5 million at Sotheby’s in November 2015. The Cullinan-sourced blue gem eclipsed the previous record, held by “The Graff Pink”, which sold for $46,158,674 at Sotheby’s Geneva in 2010.
To date, Cullinan has produced over 800 stones weighing more than 100 carats. According to The National Jeweler website, 140 stones weighed more than 200 carats, and around a quarter of all diamonds weighed more than 400 carats. According to Cullinan Diamonds, the mine’s official website, the Cullinan Diamond Mine is expected to produce one million carats per year over the next 20 to 40 years.