Although diamonds have been known since antiquity they were incredibly rare until the late 1800s. For centuries the only location they were sourced from was India and the only people to own them were royalty or the very wealthy. Many legends and traditions grew up around this unique gemstone that had incredible physical properties and was so difficult to find. Diamonds seemed indestructible because of their unparalleled hardness (the name diamond comes from the Greek ‘adamas’ meaning invincible, although we now know diamonds can be broken reasonably easily), and even as unpolished crystals they often have a superb lustre. Until the fourteenth century they were not able to be polished and were used in jewellery in their rough state.
In 1725 diamonds were discovered in Brazil. By this time production from India was beginning to diminish and Brazil was able to take its place as principal supplier in the market. Diamonds remained very rare though, particularly as the primary sources of the stone remained a mystery. They were sourced from riverbeds and the gravels left from ancient rivers and it was not understood how they formed or how they came to be there.
Probably the most important diamond discovery in history was made in 1867 in South Africa. It sparked a chain of further discoveries that would lead to the unlocking of the mystery of how diamonds form and where they might be found. The diamond deposits discovered in South Africa were not following either current or ancient rivers and gems continued to be found as mining progressed deeper into the ground, whereas previous riverbed sources had only been reasonably close to the surface.
Diamonds form deep in the earth’s mantle in regions completely inaccessible to humans. Volcanic activity forces them up to the surface where they become trapped in the molten rock as it cools, forming extensive ‘pipes’ of rock known as kimberlite that can contain diamonds. Miners in South Africa had by chance begun mining these ‘pipes’ and were for the first time extracting diamonds directly from the rock that had transported them to the earth’s surface. This was important because it meant that more diamonds were able to be recovered, and in a greater variety of sizes and qualities than previously. It also gave prospectors an improved understanding of where to look for diamond deposits which led to a huge increase in the discovery of new mines over the following decades.
Suddenly diamonds flooded onto the market, offering many more people the chance to own them. A combination of increased availability and improvements in cutting and polishing techniques allowed much more efficient use of rough material. Smaller stones were available in greater quantities leading to a fashion for cluster designs accessible to more than just the wealthiest in society.
Throughout the twentieth century more deposits of diamonds were discovered in various locations around the globe. In Africa several countries have joined South Africa as significant producers: Namibia has large deposits along its coastline, producing a high proportion of fine material (it is thought that these diamonds originated in the kimberlite pipes of South Africa and have been transported by rivers towards the coastline where they have settled), while Botswana has risen to become one of the largest producers of diamonds in the world. Another of the largest suppliers is Russia. Cut off from traditional sources during the Cold War, Russia invested heavily in searching for diamond deposits in Siberia; they were successful and now have some of the largest mines in the world.
Australia is home to one of the world’s most famous diamond mines. The Argyle mine produces mostly brown stones which are marketed as ‘cognac’ or ‘chocolate’ diamonds, but it is most famous for its pink stones which are rare and highly coveted.
In the last 25 years Canada has also joined the ranks of major diamond producers meaning that diamonds really do come from all over the world! While no longer the preserve of royalty and the aristocracy, diamonds of the quality suitable for jewellery are still a rare material. Hundreds of tonnes of rock must be mined, crushed and sorted for even a tiny handful of diamonds that can be used in jewellery to be found, so wherever in the world your diamond comes from you can be sure it is a special piece of earth’s history that deserves to be treasured in your jewellery.