Diamond Formation
More than a billion years ago, carbon atoms were tightly bound together in a pot-shaped depression of extreme heat and pressure 100 miles (161 kilometers) or more below the Earth’s surface.Celsius (1150degrees Celsius) and at pressures 45,000 times that at sea level, a crystal is formed: diamond, the hardest naturally occurring mineral on Earth.
Diamonds lay buried deep within the Earth for hundreds of millions of years until violent volcanic activity brought them to the surface in the form of magma. Vertical rock formations called kimberlite pipes are the remains of these ancient volcanoes. Over time, erosion stripped these rough diamonds from their parent rock. These diamond crystals were carried by flowing rivers and streams, eventually ending up in river gravel and mud, often far from their original location. Until the late 1800s, the world’s diamonds were discovered and mined in these alluvial deposits.
Today, most diamonds are found in kimberlite pipes, which are the primary source of mined diamonds.
The modern diamond industry began with the discovery of kimberlite pipes in South Africa in 1869. Mining followed, producing tens of millions of carats of rough diamonds each year—including a major discovery in Botswana in 1967, and other locations in Africa, Australia, Siberia and Canada’s Northwest Territories.
By the end of the 20th century, diamonds were no longer the only source of land. In 1970, General Electric began growing diamonds in a laboratory, and sold the first gem-quality lab-grown diamond in 1984. As technology improved, man-made diamonds became more common and harder to detect. Learn about lab-grown diamonds .
Identification of origin
Determining the origin of a diamond is challenging. Unlike some colored gemstones, the origin of a natural diamond cannot be determined by close examination of a polished stone. Data must be collected at the time of extraction and the rough diamond must be analyzed first. Using a patented GIA-developed technology called Scientific Match, GIA diamond graders match the characteristics of a polished diamond to the rough diamond and analyze them to confirm the polished diamond’s country of origin.
GIA and other diamond laboratories evaluate the quality of polished diamonds using the 4Cs of Diamond Quality (Color, Clarity, Cut and Carat Weight), an international standard developed by GIA. However, only GIA can confirm the country of origin of your diamond through a scientific process. The GIA Diamond Origin Report contains a complete and unbiased 4Cs assessment of your diamond’s quality, clearly identifying your diamond’s country of origin. Learn about the GIA Diamond Origin Report .
