Diamond: Fun Facts

Diamond rough and cut diamond from Botswana

April’s birthstone. The hardest natural substance on Earth. More than a billion years old.

There’s a wealth of history and knowledge surrounding diamonds. This popular gem is brilliant, glamorous, breathtaking and mysterious. And you’ll add intriguing to the list after you read through these fun facts about diamonds.

Did You Know?

  • Diamonds were being used to engrave gemstones in India by 300 BCE.
  • Diamonds can be burned. To burn a diamond, it must be heated to between 1290 and 1650 degrees Fahrenheit (700 and 900 degrees Celsius). House fires and jewellers’ torches can sometimes reach that temperature.
  • D-to-Z colour diamonds are the most widely used in jewellery, but diamonds come in all colours of the rainbow. For natural coloured diamonds, blue, green, orange and red are the rarest; yellow and brown are the most common.
  • Diamond weight is measured in carats (not carrots or karats). The word carat is derived from keration, the Greek name for the carob tree whose seed was used for centuries as the standard for weighing precious stones. Because the seed could vary slightly in weight, in 1913, carat weight became metric; one metric carat is equivalent to 0.2 grams or 0.007 ounces.
  • The largest rough diamond, discovered in 1905, is the Cullinan diamond, weighing in at 3,106 carats (ct.)!
Fancy Colour Diamonds
Courtesy of Alan Bronstein and Aurora Gems. Photo: Robert Weldon/GIA

Where do diamonds come from?

  • Diamonds were formed billions of years ago through a combination of tremendous pressure and temperatures of 1652–2372 degrees Fahrenheit (900–1300 degrees Celsius) at depths of between 90 and 120 miles beneath Earth’s surface.
  • Diamond crystals are brought closer to the Earth’s surface through volcanic activity.
  • Diamonds can be found in shallow alluvial deposits where the crystals settle after being transported away from the kimberlite pipes by geologic activity and rivers.
  • Around 30 per cent of the diamonds mined worldwide are gem-quality.
  • Prior to the 18th century, most diamonds were found in India.
  • Diamonds were discovered in South America as early as 1725. The discovery occurred in Minas Gerais, Brazil, just as the production in India was dwindling.
  • Diamonds were found in North America in the 1840s, although this was soon eclipsed by the discovery of diamonds in Africa in the late 1860s and early 1870s and the ensuing Great Diamond Rush.
  • In 2014, Russia produced the most diamonds by volume and value.
  • With the opening of the Ekati mine in late 1988, and others in Canada, North America produces almost 10 per cent of the total world diamond production by volume.
  • Even though the U.S. produces almost no diamonds for commercial consumption, America buys more than 40 per cent of the world’s gem quality diamonds – making it the world’s largest diamond market.

Now that you know some fun facts about diamonds and where they come from, take a look at some of the most famous diamonds ever found.

The Hope Diamond

Courtesy of Chip Clark, Smithsonian Institution. http://geogallery.si.edu/
Courtesy of Chip Clark, Smithsonian Institution. http://geogallery.si.edu/
  • The Hope Diamond, a Fancy dark greyish blue diamond, fashioned into a cushion brilliant cut, was originally 112 ct. before being cut to its present weight of 45.52 ct.
  • The Hope Diamond is said to be cursed. Although one of its owners, Evalyn McLean believed it to be her good luck charm, her life states otherwise; after possession of the gem, her young son died in a car accident, her husband divorced her and died insane, and her daughter committed suicide.
  • The Hope Diamond, perhaps the world’s most legendary gem, arrived at its present home at the Smithsonian Institution on 10 November 1958 via the U.S. mail – albeit registered first class!

The Uncle Sam Diamond

The Uncle Sam Diamond
  • To date the Uncle Sam, discovered in 1924, is the largest diamond ever found in the U.S.
  • It was found in the world’s only diamond mine open to the public. The Crater of Diamonds State Park in Arkansas is a dig-for-fee operation for tourists and amateur geologists.
  • Since 1906, more than 70,000 diamonds have been discovered there, including the Uncle Sam diamond, weighing 40.23 ct.

In 2015, a park visitor found an 8.52 ct. diamond at the same park that the Uncle Sam diamond was discovered at.

The Cullinan Diamond

Photo by Peter Macdiarmid/Getty Images
Photo by Peter Macdiarmid/Getty Images
  • The historic Cullinan diamond, found in South Africa in 1905, weighed an astounding 3,106 ct. It was cut into a total of 105 diamonds of exceptional colour and clarity.
  • The Great Star of Africa (Cullinan I) weighs 530.20 ct. and the Lesser Star of Africa (Cullinan II) weighs 317.40 ct. These two diamonds are part of the crown jewels of Great Britain.
  • The Cullinan III to Cullinan IX, and the remaining 96 diamonds cut from the Cullinan are in private collections.
  • The two largest stones are mounted in the British crown jewels, while eight others are part of Queen Elizabeth II’s private collection.

The Wittelsbach-Graff Diamond

Photo by Robert Weldon/GIA
Photo by Robert Weldon/GIA
  • The 31.06 ct. Wittelsbach-Graff is one of the largest historic blue diamonds ever fashioned.
  • Blue diamonds are extremely rare. The presence of boron impurities is often responsible for the colour of natural blue diamonds. However, their colour can also be caused by radiation exposure or associated with hydrogen. Blue diamonds naturally coloured by exposure to radiation are usually described as green-blue, whereas those with colour that is associated with hydrogen are described as grey-violet to grey-blue.
  • The diamond belonged to the Bavarian House of Wittelsbach and was displayed in the Treasury of the Munich Residence until it disappeared in 1931. It was secretly sold in 1951, "rediscovered" in 1961, and then sold again in 1964 to an undisclosed private buyer.
  • In December 2008, the Wittelsbach-Graff (then called the Wittelsbach Blue) was sold at Christie’s London to jeweller Laurence Graff for just over $24.3 million.
  • The stone is graded Fancy Deep blue with IF clarity.
  • Because the Wittelsbach-Graff Diamond and the Hope Diamond have similar colour and long-lasting phosphorescence – and both are believed to have been mined in India – there has been widespread speculation that they were cut from the same crystal. But were they? Research published in the Summer 2010 issue of Gems & Gemology indicates that the two diamonds do not share a common parent.

Want to learn more? Check out diamond in the GIA Gem Encyclopaedia to read more about the history, lore and scientific research surrounding this beloved gemstone.