Diamond

Diamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. At room temperature and pressure, another solid form of carbon known as graphite is the chemically stable form, but diamond almost never converts to it. Diamond has the highest hardness and thermal conductivity of any natural material, properties that are utilized in major industrial applications such as cutting and polishing tools. They are also the reason that diamond anvil cells can subject materials to pressures found deep in the Earth.
Cullinan Diamond

The Cullinan Diamond is the largest gem-quality rough diamond ever found, weighing 3,106.75 carats (621.35 g), discovered at the Premier No. 2 mine in Cullinan, South Africa, on 26 January 1905. It was named after Thomas Cullinan, the mine's chairman.
Golden Jubilee Diamond

The Golden Jubilee Diamond is the largest cut and faceted diamond in the world. It weighs 545.67 carats. It outweighs the Cullinan I by 15.37 carats. The Golden Jubilee Diamond was discovered in the Premier Mine, which is also the origin of the Cullinan diamond (1905) and other notables such as the Taylor–Burton (1966) and the Centenary (1986). Cullinan I, also known as the Great Star of Africa, had held the title of the largest cut and faceted diamond since 1908.
Cullinan, Gauteng

Cullinan is a small town 30 km (19 mi) east of Pretoria, Gauteng, South Africa. It is a small town along the diamond route that is heavily reliant on tourism and the mine that dominates the skyline. The town is named after diamond magnate Sir Thomas Cullinan.
List of diamonds

A number of large diamonds have gained fame, both as examples of the beautiful nature of diamonds and because of the famous people who wore, bought, and sold them. A partial list of famous diamonds in history follows.
Excelsior Diamond

The Excelsior Diamond is a gem-quality diamond, and was the largest known diamond in the world from the time of its discovery in 1893 until 1905, when the larger Cullinan Diamond was found. It was found on June 30, 1893 at the Jagersfontein Mine in South Africa, 130 kilometres south east of Kimberley whose fame as a diamond mining center always overshadowed that of Jagersfontein. It had a blue-white tint and weighed 971 old carats or 995.2 metric carats. The Excelsior rates as the third largest rough diamond of gem quality ever found. It was ultimately cut into ten stones weighing from 13 to 68 carats..
Harry Winston

Harry Winston was an American jeweler. He donated the Hope Diamond to the Smithsonian Institution in 1958 after owning it for a decade. He also traded the Portuguese Diamond to the Smithsonian in 1963.
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 (10,000 ft) it is the world's highest diamond mine.
Diamond (gemstone)

A diamond is one of the best-known and most sought-after gemstones. Diamonds have been used as decorative items since ancient times; some of the earliest references can be traced to 25,000 - 30,000 B.C.
Petra Diamonds

Petra Diamonds Ltd is a diamond mining group headquartered in Jersey. It has a diversified portfolio, with interests in eight producing mines in South Africa and Tanzania and an exploration programme in Botswana. Petra Diamonds' focus has shifted from exploration to production, becoming one of the largest independent producers of diamonds in Africa. In June 2012, Petra owns 5 of the world's most productive mines historically. These mines include the Cullinan Diamond Mine famed for having produced the world's largest rough and polished diamond. It is listed on the London Stock Exchange.
Brown diamonds
Brown diamonds are the most common color variety of natural diamonds. In most mines, brown diamonds account for 15% of production. The brown color makes them less attractive as gemstones because of the reduced glimmer, and most are used for industrial purposes. However, improved marketing programs, especially in Australia and the United States, have resulted in brown diamonds becoming valued as gemstones and even referred to as chocolate diamonds.
Lucara Diamond

Lucara Diamond Corp. is a diamond exploration and mining company, operating in southern Africa but established in Canada. In November 2015, Lesedi La Rona, the world's second largest gem-quality diamond ever found, was found at the Karowe mine in Botswana.
Lesedi La Rona

Lesedi La Rona, formerly known in media as Karowe AK6 or as Quad 1 by the personnel at the mine, is the third-largest diamond ever found, and the second-largest of gem quality. Only the non-gem black Sergio and the gem-quality Cullinan were larger. It was found in the Karowe mine, in Botswana on 16 November 2015.