A Diamond's Journey

A diamond is a mineral composed of 99.5% pure carbon that is crystallized in an isometric arrangement. The remaining 0.05% consists of impure elements that often influence the crystal's color or shape.


Diamonds are formed deep inside the mantle of the earth‟s crust, 75 to 120 miles beneath the surface, where the necessary temperature and pressure conditions exist to form the gem. As a result of powerful volcanic activity 2.5 billion – 45 million years ago, diamonds arrived at the earth‟s surface. The volcanic activity created openings called pipes, and forced the diamonds, along with other minerals like kimberlite, up to the surface. After these eruptions some diamonds settled back into the kimberlite pipes, while others were washed hundreds of miles via floods, rivers and oceans, creating alluvial deposits.

While diamonds can‟t be dated, the materials found around them can. The youngest diamonds on Earth appear to be hundreds of millions of years old, and older ones stretch back billions of years.

Where Diamonds Come From

The first diamonds were found in alluvial deposits in southern India, before 500 BC. For centuries, India remained the world's primary source of diamonds, though these deposits never produced substantial quantities. This changed with the discovery of large diamond deposits in Brazil in 1725. Over a century later, around 1870, diamonds were found by farmers in South African rivers and fields. Soon after, kimberlite pipes containing diamonds were also uncovered. These findings opened an era of continual discoveries, as geologists learned how to locate and identify other potential sources.

Although large quantities are found in only a few places, diamonds have been found in every continent except Antarctica. In the past 30 years, major discoveries have occurred in Botswana, Australia, Russia, and China. Today, natural diamonds are mined in approximately 25 countries across five continents. Africa, Russia, and Canada account for more than 90% of the world‟s natural gem-quality diamond production, which exceeds 80 million carats of gem-quality diamonds per year.

Diamond Mining

The methods used in mining diamonds can vary greatly in cost and efficiency. Some diamonds remain hidden in their kimberlite pipes, while others were washed along the earth leaving alluvial deposits.

Pipe mining starts with the excavation of a pit that leads into the kimberlite pipe. In the bedrock adjacent to the pit, shafts are created that can extend 3,600 feet beneath the earth's surface. The ore within the pipe is blasted loose and taken to a processing plant to separate the diamond from the rock.

Alluvial mining can range from primitive pan mining with pie tins to complex processes involving massive machinery capable of scooping 1,800 tons of sand. The sand and gravel are scooped and then carefully sifted. More than 200 tons of rock, gravel, and sand need to be blasted, crushed, sieved and processed to yield a single one-carat, polished, gem-quality diamond. More than 100 million carats are mined each year, but 80% of the rough diamonds found are used for industrial purposes, leaving only 20% suitable for gem quality.

Bringing Rough Diamonds to Market

The majority of the world‟s rough diamond supply is first handled by the DeBeers Central Selling Organization. The CSO sorts the diamonds into different categories of size, shape, and color, then prices them accordingly. Batches of rough diamonds are then sold to a small number of authorized bulk purchasers called sightholders. These sales, called “sights” are held ten times a year and are by invitation only. The balance of the rough supply is distributed to private buyers and through private auctions.


The next step for the rough diamond is cutting and polishing by artisans, using techniques perfected over generations. The rough diamonds are distributed to the 5 main diamond cutting and trading centers in the world, located in Antwerp, Tel-Aviv, Bombay, Johannesburg, and New York. Each rough diamond is carefully examined in order to determine which cut will yield the greatest value. The diamonds are marked for sawing and cleaving, and then go through several processes, most performed by hand, before they are polished and ready for sale at one of the 24 registered diamond bourses around the world.

The finished product is sold or traded to other jewelry manufacturers, diamond wholesalers, and retail jewelry stores. Today's technology has changed the pipeline of diamond distribution, allowing the consumer to have a more direct link to a diamond, without having to go through traditional middlemen and the markups that happen with each transaction