What is a diamond?

Diamond Buyer's Guide

Every item of diamond jewellery is a small miracle. The diamonds that are used in jewellery were formed from carbon deposits millions and sometimes billions of years ago, deep under the earth in intense heat and pressure. From here they were carried by powerful lava flows to the earth's surface, and millions of years later they were mined by us and turned into the diamond jewellery that we now wear. Even after this incredible journey, only half of the diamonds mined are of gem quality, so it is no surprise that we consider diamonds to be rare and priceless and full of magical qualities. If you want to find out even more detail about this incredible process read on.

Rare and precious diamonds

As well as being a scientific miracle, a diamond is also the ultimate symbol of love. No other gem is as rare, indestructible, beautiful or magical, steeped in history, or so closely associated to one of the central traditions of our culture - marriage. Every item of diamond jewellery sold, whether it is a diamond engagement ring, necklace or other piece of jewellery, symbolises commitment, strength and the everlasting nature of love. It is hard to imagine that this gem started out billions of years ago as a piece of carbon buried miles beneath the surface of the earth.

What is carbon?

Diamonds are formed from pure carbon at a depth of around 90 miles over a period of millions of years. Carbon is the fourth most abundant element in the universe by mass and the second most abundant element by mass in the human body (about 18.5%) after oxygen. When combined with the fact that it is present in all known lifeforms and has unusual polyforming abilities in the temperatures found on earth, carbon can easily be seen to be the chemical basis of all known life. Diamonds are one of the purest and most revered forms of carbon and you could say that, when you give diamond jewellery, you are giving purity, strength and a symbol of the very essence of existence.

How is carbon turned into diamonds?

In simple terms, a diamond is a piece of carbon that has had intense heat and pressure applied to it far below sea level and is then carried through molten lava flows to the earth's surface where it is mined and, in turn, made into the sparkling diamonds that we use in our jewellery. However, of all the diamonds mined only half are of gem quality, and even fewer are big enough to be made into a polished stone no bigger than a match head. The carbon to make diamonds can come from non organic sources, organic sources, or a blend of the two. In other words, if any carbon is subject to the conditions required to create diamonds it will become diamonds, no matter its original state.

Diamond heat

Carbon requires heat in the range of 1100 Celsius (2000 Fahrenheit) to become diamonds. Any hotter than this and it will be too hot for them to form. Diamonds are formed over centuries and most diamonds are over billions of years old by the time they are mined and turned into your jewellery, almost as old as the planet earth itself. So, when you choose your diamond engagement ring, you really are offering everlasting love.

Deep feelings

Because diamonds require incredible temperatures they are formed far below the earth's surface. Diamonds are delivered up to the earth's surface by flowing magma from depths up to three to four times more than normal volcanoes. As a result, these magma flows are relatively rare, again contributing to the uniqueness of diamonds. But when they do occur and the magma cools, a rock formation called kimberlite, otherwise known as lamproite, is left behind. This is one of the prime markers of a diamond deposit for miners.

Diamond mining

Mining into one of these deposits, known as kimberlite dikes or pipes, you are likely to discover diamonds. Kimberlite doesn't guarantee the presence of diamonds, but does indicate that the volcanic activity that resulted in this deposit has come from a place deep enough to contain diamonds. Diamonds can also be found in other places. Sometimes ancient glacial movements may have moved the diamonds from where they originally surfaced. Diamonds have also, occasionally, been formed where meteorites have had an impact with the earth.

Where on earth?

India has been the primary source of diamonds for centuries, almost depleting their deposits. These days almost half of the diamonds mined come from Southern and Central Africa. However, large mines also exist in Brazil, Australia, Siberia and parts of Canada.

Diamonds: history, glamour and style

Diamonds, formed at the heart of the earth at extreme temperatures, from the building blocks of life itself, are the perfect choice for expressing your love and the ideal way to say, 'I love you forever!'