Cullinan (previously named Premier) is situated in the town of Cullinan, 40 kilometres east of Pretoria, Gauteng Province, South Africa. 
Cullinan is one of the world’s most celebrated diamond mines and is renowned for producing many of the most spectacular diamonds ever seen. It earned its place in history with the discovery of the Cullinan diamond in 1905, the largest gem diamond ever found at 3,106 carats rough, and it has produced more than a quarter of all the world’s diamonds weighing more than 400 carats. It is also the world’s only significant source of truly rare and highly valuable blue diamonds.
The Cullinan kimberlite pipe is the second largest indicated diamond resource in the world by in-situ value and totals some 208 million carats (including tailings). 

Brief Characteristics of the mine:
Size of kimberlite pipe – 32 hectares at surface 
Start of mining operations – 1903 
Ownership – Petra Diamonds Limited: initial 37% (option to increase to 60%), Al Rajhi Holdings W.L.L.: initial 37%, Thembinkosi Mining Investments (Pty) Ltd: 14%, Petra Diamonds Employee Share Trust: 12% 
Operator – Petra Diamonds 
Total resources – 207.9 million carats 
Type of mining – Underground block cave 
Depth of mining – 747 meters

History
The mine was established in 1902 as Premier Mine, it was renamed as Cullinan Diamond Mine in November 2003 in celebration of its centenary. The mine rose to prominence in 1905, when the Cullinan Diamond — at the time the largest gem diamond ever — was discovered here. It is also the only significant source of blue diamonds in the world.
The discovery of the Cullinan mine occurred in 1890 by a Dutchman named Fabricius. He was actually prospecting for Henry Ward, who had an option to purchase the Wessels estate within a certain amount of time. However, Mr. Ward did not have any money to actually purchase the land and could have only done so if the land held diamonds, since it would be easy to find investors for it then. Ward became very fortunate when only a small part of the Wessels estate actually fell within the Cape Colony, and it was upon that portion of the land that the mine was discovered.