Introducing Diamonds

This guide is designed to give you a brief overview of the journey that a diamond takes from the heart of the earth to becoming the stunning item of jewellery; full of brilliance, mystery and the ultimate gift of love…

in the beginning

We shall begin our look at diamonds at the very beginning of time, long before dinosaurs, no less than 500,000 years ago for it was then that these amazing natural stones were first formed by the great heat and pressure of primeval volcanic action.

The chemical composition of the extraordinary crystals formed in the molten rock was pure, crystalline carbon and when these crystals grow they produce the hardest natural substance known to man – the substance we call: Diamond.

where do diamonds come from?

Diamonds are not found all bright and shiny as we see them in the finished item of jewellery, indeed in their natural, uncut “rough” state they could be mistaken for pebbles.

The molten, volcanic rock in which diamond crystals were formed millennia ago is called Kimberlite. This is bluish green in colour and is sometimes called “Blue Ground”. It can be found all over the world but only a small number of Kimberlite sites, or pipes as they are called, contain the precious crystals of diamond.

why are diamonds so valuable?

There are several reasons why diamonds command such high prices. Firstly, very few Kimberlite pipes actually contain diamonds, and when they do gem quality diamonds are only a tiny percentage of their yield. Secondly, diamond mines tend to be in very inhospitable places – beyond the Arctic Circle, at the bottom of the lakes or sea and deep in arid deserts – this makes the cost of extraction very high. It is also difficult to extract diamonds from the earth once a site has been discovered. The first task is to dig down from the top, recover the rock, crush it and extract the diamonds. When the hole becomes too deep a shaft is sunk alongside the pipe and mining continues from the side.

However, not all diamonds remain locked within the Kimberlite pipes. Over millions of years some of the pipes have weathered and the diamonds have been washed away by rivers and floods, often as far as the sea. These diamond deposits are called alluvial.

Mining these alluvial stones presents particular problems. Not only are the diamonds mixed with sand and gravel, they are also buried under thousands of tonnes of it. This page shows pictures of beach mining and what is called “conglomerate”. This is the gravel, found just above the bedrock that includes the rough diamond crystals.

Deep water and ocean mining present other problems and require huge capital investment in ships and other technical equipment and in today’s conservation-mined world the mining companies have to guarantee to restore the sites back to their natural state once extraction is complete, so adding to the final cost.