[The Nature of Diamonds - San Diego Natural History Museum]

Facts About Diamonds
  • Most diamonds are over three billion years old, two-thirds the age of the Earth. There are a few "youngsters," though, which are only 100 million years old.

  • Most diamonds were formed more than 100 miles below the surface of the Earth, some from perhaps 400 miles down.

  • The most recent kimberlite volcano eruption was approximately 53 million years ago - just a few ticks of the geologic clock - but there is no reason to believe there will not be more in the future.

  • Although diamonds are perceived as a white—actually colorless—gem, they come in a spectrum of colors; colored diamonds are called "fancies."

  • India was the only known source of diamonds before the sixth century and the predominant source for over 2,000 years, until the mid-eighteenth century.

  • Romans believed that diamonds had the power to ward off evil and wore them as talismans. They inherited this belief from Indian mythology.

  • A law in thirteenth-century France decreed that only the king could wear diamonds.

  • Diamonds were not used as gems in European jewelry until the late 13th century. They were initially used for such purposes as engraving other gems, such as sapphire cameos, and for drilling holes in hardstone beads (such beads drilled by diamonds have been dated to archaeological sites as early as 400 BCE).

  • The most recent diamond discoveries have been made in North America—in the Northwest Territories of Canada and in Colorado—where explorers found diamond pipes in 1990.

  • Some diamonds are composed of carbon, that is recycled organic matter, previously incorporated in marine organisms.

  • "One-hour eyeglasses" have only become possible with the use of diamond tools, which can quickly and accurately shape the lenses.

  • Because diamonds can withstand extremely high temperatures and corrosive conditions, and because they are transparent to most forms of light and electromagnetic radiation, they are ideal for use as windows in industry and in space probes, including the 1978 Pioneer space probe to the surface of Venus.

  • Every copper wire in your computer, television, and house has been shaped with a die—the device that squeezes wire to the desired diameter—made from diamond.

  • Diamond scalpels are particularly effective because their sharp, hard edges never dull, and, because diamond's hydrophobic surface—its resistance to being wetted—ensures that wet tissue does not adhere to the blade.

  • The largest rough diamond ever found was the Cullinan, 3,106 carats, discovered on January 26, 1905 in the Premier mine of South Africa. It was cut into nine major stones, including the largest gem diamond, the Cullinan 1, or Star of Africa, 550.20 carats. This is mounted in the British Royal Scepter and housed in the Tower of London.

  • In the 1950s, Gemological Institute of America developed the first internationally accepted diamond grading system. This system provides unbiased opinions of the quality of polished diamonds by applying uniform criteria to their grading.

  • The GIA Gem Trade Laboratory Diamond Grading Report has become the benchmark for the international gem and jewelry industry, and can be found accompany diamonds worldwide.

Nature of Diamonds | Exhibits