FAMOUS DIAMOND

Today a handful of diamonds have come to be known as symbols of history, legacy and magical lore. They own grand names to mark their significance and behind each of these spectacular diamonds lay a rich, magnificent story of history, discovery and technical achievement.

De Beers Millennium Star

A diamond so flawless and so great in size that the world's diamond experts cannot put a price on it. Discovered in the Republic of the Congo , De Beers mined the Star in the early nineties. It took over three years for their diamond cutters to shape the stone with lasers. What emerged was the world's only internally and externally flawless, 203-carat, pear-shaped diamond.

The Koh-i-Noor

No stone on earth has as rich and fascinating a history as the Koh-i-noor. The lineage of this great diamond began in 1304 when it was held by the Rajah of Malwa. This was a time when possession of such a gem symbolized the power of an empire. In fact, it has been said that he who owns the Koh-i-noor rules the world. In 1738, after successfully invading Delhi , the next conquest of Nadir Shah of Persia was to acquire the great stone. Legend has it that a member of Emperor Mohammed Shah's harem informed Nadir Shah that the jewel was kept hidden in the emperor's turban.

Later that night, when Nadir Sha h unfolded the host's turban he discovered the gem. Upon seeing it he exclaimed, "Koh-i-noor," meaning "mountain of light." Nadir Shah then brought the jewel back to Persia . There it remained until 1849 when the British annexed the Punjab and took possession of it.

Three years later, after a public viewing in London , crowds expressed disappointment in the lack of brilliance in the stone. So it was decided that the gem be re-cut to accentuate its brilliance, thereby reducing its size from the 186-carat diamond to its present size of 108.93-carats.

In 1853, there was some question as to whether Queen Victoria would return the grand stone for fear of the misfortune it was rumored to bring. She answered the query by having it mounted in a tiara, joining more than two thousand other royal diamonds.

Toady the legal ownership of the Koh-i-Noor still remains a wrangle among world leaders vying for its possession.

Cullinan

In 1905, as miners filed out after a long day in South Africa 's Premier mine, one miner noticed what appeared to be a shiny object lodged in the earth. With nothing more than a pocket knife, he pried it lose from the ground and presented it to his mine manager. This humble discovery is regarded today as one of the greatest diamond discoveries of all time.

When no buyers were found for the great stone, it was decided that the diamond would be made into a gift for King Edward VII of England . It was decided that the great stone would be cut into two smaller stones: Cullinan I and Cullinan II. The larger of the two (Cullinan I) was renamed the "Great Star of Africa." The cutting of the Cullinan was so successful that the two new gems became part of the Crown Jewels of England .The Cullinan II, humbly measuring 1.7 x 1.5 inches, was handsomely set in the brow of the British Imperial State Crown.

The Taylor Burton

Richard Burton presented Elizabeth Taylor with one of the world's largest and most beautiful diamonds. If any gem could be noticed next to the beauty of Elizabeth Taylor it was this 69-carat, pear-shaped diamond.

The stone was unearthed at the Premier mine of South Africa in 1966. And it was Harry Winston who cut and polished the rough stone from its original size of 244-carats. It has been moving in and out of auction houses, and the last recorded sale was to an anonymous Saudi buyer for $3,000,000.

The De Beers Diamond

It was not long after De Beers Corporation set about the business of mining diamonds that their first major discovery surfaced. A stone weighing 428.5-carats was unearthed from the Kimberly mines of South Africa . At 228.5 carats after its polishing it was thought to be the worlds largest cut diamond in 1889. It has the honor of being the fourth largest cut diamond in the world.

electrical conductivity

Other specialized applications also exist or are being developed, including use as semiconductors: some blue diamonds are natural semiconductors, in contrast to most other diamonds, which are excellent electrical insulators.^[21] The conductivity and blue color originate from the boron impurity. Boron substitutes for carbon atoms in the diamond lattice, donating a hole into the valence band.^[21]

Substantial conductivity is commonly observed in nominally undoped diamond grown by chemical vapor deposition. This conductivity is associated with hydrogen-related species adsorbed at the surface, and it can be removed by annealing or other surface treatments.^[22][23