Chemical composition: C
Crystal: Isometric-Hexoctahedral (cubic)
Diamonds are the hardest natural forming mineral.
Diamonds come in many colors but the most common has always been the white or colorless. Depending on where the diamond comes from, depends on its color.
South Africa is where most people think of diamonds coming from. The most famous mine is the Premier mine that was purchased by Petra Diamonds and changed its name to the Cullinan mine after one of the most famous diamonds in the world. It is a source for oversize white diamonds as well as the highest quality blue diamonds.
Sierra Leone produces the famous Zimmi Yellow Diamonds. The yellow is so vivid that it does not resemble any other yellow diamond. Other yellow diamonds in the world seem to pale next to the Zimmi Yellow diamonds.
India is known as a leader in the world of diamonds. It has produced the Hope Diamond and the Wittelsbach-Graff Diamond.
Democratic Republic of Congo prouces most of the low grade industrial diamonds but the colored diamonds found are yellow, orange and cognac browns.
Central Africa are black diamonds and yellow diamonds. Occassionally they will find pinks, blue and/or green diamonds.
Brazil produces mostly yellow and brown diamonds. They have a strong fluorescence which gives them a green appeal. These diamonds are usually low cost diamonds. But likewise, Brazil also produce ultra-rare red diamonds and green diamonds.
Borneo prouduces brown and yellow diamonds with the occassional pink, blue or green diamonds.
Australia is home of the world famour Argyle Diamond mine. This mine is responsilble for 90% of the world’s supply of pink diamonds. While most of the diamonds are pink in color, it still produces a notable portion of the world’s champagne brown diamonds.
Angola is famed for low grade white diamonds. Yellow diamonds (aka Canary diamonds) and brown diamonds can also be found.
Arkansas, United States is known for canary yellow diamonds, purple, blue, and browns. This is the only diamond mine opened to the public.
The orange and yellow diamonds get their colors from Nitrogen atoms within the atomic lattice of the diamond. The blue light is absorbed and the yellowish hues are reflected.
The purple colored diamons are produced by the presence of hydrogen in the atomic structure of the lattice of the diamond.
The blue diamonds get their color from the element boron being present in the lattice of the diamond.
The red, pink and brown diamondsowe their color to a combination of intense pressure and heat. While still buried deep within the earth, these factors cause distortions in the crystal lattice that absorb green light, thus reflecting a pink hue. The ultra-rare red diamond is just a deeply colored pink.
The green diamonds don’t get their color until the last leg of their journey to the earth’s surface that diamonds get their green color. Just as they are about to leave the uppermost layer of the crust, these stones absorbs naturally occurring radiation, which causes them to reflect a green hue by absorbing red and yellow light.
Diamonds are also color artficially. The idea is to take diamonds with colors that are not desired – like pale yellows – and to enhance it dramatically (pale yellow to vivid yellow) or even to change it altogether to blue, purple and red.
The main methodology is called HPHT – High Pressure High Temperature. Interestingly, this same procedure that is used to enhance to strong colored diamonds can be also used to “paint” colorless diamonds. Taking cheap very light brown diamonds and turn them into D colorless diamonds.
In recent years, the chocolate diamonds have hit the market. Thirty years ago, these diamonds would have been used as cheap diamonds in industrial equipment because they didn’t have the “shiny sparklet” people were accustomed to. Now, they are being marketed as an acceptable sparkler piece of jewelry.
In 1888, Cecil Rhodes found De Beers Consilidated Mines which made De Beers the sole owner of the all the diamond mining operations in South Africa. The name came from the original owners of the farm that the mines were located. Rhodes made a strategic agreement with the London based Diamond Syndicate to provide a fixed quantity and quality of diamonds each year for a given price. This gave him a monopoly on the diamond industry. By buying up all the individual mines in process as they became known, he was able to maintain that monopoly. To this day, De Beers has maintained that monopoly through controlling how many diamonds they release to the market.
Notable Diamonds today:
The Hope Diamond: The weight of the Hope diamond for many years was reported to be 44.5 carats. In 1974 it was removed from its setting and found actually to weigh 45.52 carats. It is classified as a type IIb diamond, which are semiconductive and usually phosphoresce. The Hope diamond phosphoresces a strong red color, which will last for several seconds after exposure to short wave ultra-violet light. The diamond’s blue coloration is attributed to trace amounts of boron in the stone.
Koh-i-noor Diamond: (aka: Mountain of Light) In 1852, Prince Albert, husband of Queen Victoria, unhappy with its dull and irregular appearance, ordered it cut down from 186 carats. It emerged 42% lighter at 105.6 carats. By modern standards, it is far from perfect, in that the culet is unusually broad, giving the impression of looking into a black hole when looking at it straight on. Since the stone has a history of men fighting for it, the British royal family has a tradition that since it has brought the men so much bad luck, that only the women of the royal family can wear it.
Golden Jubilee Diamond: Discovered in the Premier Mine, which is now the Cullinan Mine in 1908. It weighs 543.67 carats and is a brown colored diamone. It is in the Royal Thai Palace as part of the Crown jewels.
Idol’s Eye diamond: It is 70.20 carats and may have been found at Golconda around 1600. But the first authentication that can be found is at a sale at Christie’s in London on July 14, 1865. It eventually wound up in Chicago when jeweler Harry Levinson bought it for his wife. It is said she like to wear it to breakfast.
Whittlesbach-Graff Diamond: 31.06 carats with internally flawless clarity, fancy deep blue diamond from the Kollur mines in Guntur District in Andhra Pradesh, India.
Star of the South: 128.48 carats and has a few flecks of titanic iron or volcanic sand. The diamond is white with a rose tint. It was found in Brazil in 1853. The color grading is fancy light pinkish-brown with a clarity of VS2.
Taylor-Burton Diamond: It was found in the Premier Mine in South Africa in 1966. It weighed 241 carats when it was found but was cut down to 69.42 by Harry Winston. After it was purchased in 1969 by Richard Burton and Elizabeth Taylor. It was worn by Liz Taylor at Princess Grace of Monaco’s fourieth birthday and at the 42nd Academy Awards. When they bought it, it was set in a platinum ring with two smaller diamonds to the either side. Taylor found it to be too heavy for a ring and had it redone into a necklace so as to hide a tracheotomy scar that Liz had.
Centenary Diamond: Third largest diamond to come from the Premier Mine. It has the top color grade of D colorless. It was 599 carats when it was found. When it was completed, it had 247 facets and weighed 273.85 carats.
Hortensia Diamond: This orangey-pink diamond is in the Crown Jewels of France. It weighs 20 carats. It is rather flat and rectangular and is cut on five sides. It gets its name from Hortense de Beauharnais, Queen of Holland, undoubtedly because she wore it. Hortense was the daughter of the Empress Josephine, the step-daughter of Napolean Bonaparte and the mother of Napoleon III.
On April 27, 2015, Sotheby’s auction house in New York, NY, sold a 100.1 carat, emerald cut, D color, internally flawless diamond is the largest of its clarity and cut to ever be shown at auction. The stone in the ring setting sold for $22.1 Million dollars in an auction that lasted for only 3 minutes.
Sotheby’s Hong Kong office sold an oval white diamond that was 118.28 carats for $30.6 Million dollars. This was the largest for this color diamond ever sold. The auction lasted a total of 6 minutes.