The Lesotho Promise, a 603 carat (121 g) diamond

Diamond

In mineralogy, diamond is an allotrope of carbon, where the carbon atoms are arranged in a variation of the face-centered cubic crystal structure called a diamond lattice. Diamond is less stable than graphite, but the conversion rate from diamond to graphite is negligible at ambient conditions...

 stone

Rock (geology)

In geology, rock or stone is a naturally occurring solid aggregate of minerals and/or mineraloids.The Earth's outer solid layer, the lithosphere, is made of rock. In general rocks are of three types, namely, igneous, sedimentary, and metamorphic...

 of exceptional colour was unearthed on 22 August 2006 at the Letseng diamond mine

Letseng diamond mine

The Letseng diamond mine, found in the landlocked Southern African kingdom of Lesotho, is owned by Gem Diamonds, Ltd. and the government of Lesotho, and at an elevation of 3,100 m it is the world's highest diamond mine.- Production :...

 in the mountain kingdom of Lesotho

Lesotho

Lesotho , officially the Kingdom of Lesotho, is a landlocked country and enclave, surrounded by the Republic of South Africa. It is just over in size with a population of approximately 2,067,000. Its capital and largest city is Maseru. Lesotho is a member of the Commonwealth of Nations. The name...

. Announced on the 4th of October 2006, it is the largest reported find this century and the 15th largest diamond ever found. The stone is rated 'D'

Diamond color

A chemically pure and structurally perfect diamond is perfectly transparent with no hue, or color. However, in reality almost no gem-sized natural diamonds are absolutely perfect. The color of a diamond may be affected by chemical impurities and/or structural defects in the crystal lattice...

, the top colour band for diamonds.

The diamond was sold at an auction

Auction

An auction is a process of buying and selling goods or services by offering them up for bid, taking bids, and then selling the item to the highest bidder...

 on 9 October 2006 in Antwerp, Belgium

Belgium

Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...

, for US$

United States dollar

The United States dollar , also referred to as the American dollar, is the official currency of the United States of America. It is divided into 100 smaller units called cents or pennies....

12.4 million. The buyer, The South African Diamond Corporation (SAFDICO), expects to sell the diamond for more than 20 million dollars after cutting.

In July 2007 the finished stones were unveiled. The largest gem cut from the crystal is a 75 carats (15 g) pear-shaped diamond, and the smallest is a 0.55 carats (110 mg) round brilliant. In all, twenty-six stones were fashioned from the rough gem, figuring as seven pear shapes, four emerald cuts, thirteen round brilliants and one heart shape. The finished gems total 224 carats (44.8 g).

The Lesotho Brown (usually simply called the Lesotho) at 601 carats (120 g) was the largest diamond previously found at the mine.