A diamond is one of nature’s most precious gifts. Adorned with normal patterns and unique resilience, a diamond’s journey is nothing short of extraordinary. Crafted into high jewellery and wedding collections, diamonds undergo a magnificent process, starting deep below the earth’s surface.
How are diamonds made?
Natural diamonds can be formed in at least four different ways, however just one of these processes accounts for nearly all of the diamonds we see today. This process comes directly from the earth’s mantle.
Natural diamonds were born deep below the earth’s surface in environments of extreme pressure and temperature. At depths of over 120km and heat between 900°C and 1300°C carbon begins to crystallise and form diamonds. Over time, the carbon atoms bond in a tetrahedral lattice arrangement, creating the strong, rigid structure that characterises diamonds. Other ways that diamonds are formed include:
- Subduction zones: diamonds are pushed by tectonic plates and then return to the surface with tiny diamonds
- Impact sites: a result of the earth being subjected to astroids which results in intense pressures and temperatures
- Formation in space: some researchers have found large amounts of nanodiamonds in meteorites however these are far to small to use for any type of jewellery
Most natural diamonds date back millions, if not billions of years and may not always have gone through an uninterrupted process. A rough diamond’s formation can be disturbed due to a change in temperature or pressure. The gemstone may then wait hundreds or even millions of years for conditions to be suitable and growth to continue.
Where are diamonds found?
Diamonds are formed around 200 kilometres below the earth’s surface, however, diamonds are actually found and collected near to the surface in special kimberlites. Geologists believe that nearly 100% of the diamonds found in diamond mines were formed in the upper mantle and delivered to the earth’s surface by a deep-source volcanic eruption.
Volcanic eruptions happen when trapped gas gets too hot and starts expanding and rising. This causes a part of the mantle to melt into magma. As the magma cools, it hardens to form the rock called kimberlite, mainly in vertical structures known as kimberlite pipes. These are the most significant sources of diamonds, accounting for nearly all natural diamonds. As the gas escapes towards the Earth’s surface, the rocks and diamonds located around it will also be transported.
How are diamonds mined?
Diamonds are mined using several methods, each depending on the location and nature of the diamond deposits. Each of these mining methods has its own environmental and economic considerations with many modern mining companies investing in sustainable practices to minimise their impact on the environment and local communities.
Open-pit mining
Used when diamonds are found near the surface, open-pit mining involves removing the overburden, which is the soil and rock covering the diamond deposit, to extract the diamond-bearing ore. The ore is then transported to a processing plant where it is crushed and screened to separate the diamonds from the rock.
Underground mining
For deeper diamond deposits, underground mining is employed which involves tunnelling deep into the Earth to reach the diamond-bearing rock. Various techniques, including room-and-pillar, block caving, and sub-level caving, are used to extract the ore where it is then transported to ground level.
Alluvial mining
Alluvial mining is used when diamonds have been transported away from their primary source by natural forces such as rivers and natural events. This method involves extracting diamonds from riverbeds or coastal areas where they have settled over time and will involve techniques such as panning, sluicing, and dredging.
Marine mining
Specialised ships equipped with advanced technology extract diamonds by vacuuming sediment from the seabed which is then processed onboard to extract the diamonds. This method allows for the recovery of diamonds from locations that are considered inaccessible.
Artisanal mining
Artisanal mining is a small-scale, manual method often used in remote areas. Individual miners or small groups dig and sift through soil and gravel by hand to find diamonds. This labour-intensive process requires minimal equipment and often relies on the miners’ skills and knowledge.
How are coloured diamonds made?
Whilst the classic white diamond is adorned by many, coloured diamonds, often referred to as fancy diamonds, are also an exquisite feature when it comes to high jewellery collections. Often gifted for anniversaries, birthdays or weddings, coloured diamonds are formed in a very similar way to a colourless diamond however relies on certain trace elements and structural anomalies during the formation process. These unique factors interact with light in various ways, producing the stunning array of colours that make coloured diamonds so highly prized and valued.
What is the difference between a lab grown diamond and a natural diamond?
A mined diamond has been sought after since the introduction of diamond jewellery but the past few decades have made way for a comparative alternative, lab grown diamonds. By the 1950s, scientists harnessed the intense heat and pressure required to create synthetic diamonds in a lab. The main difference between the two is simple. A natural diamond has been formed and extracted naturally, from the earth’s mantel, and a lab grown diamond has been formed in a lab.
Diamond Jewellery Handcrafted by David Morris
Located on Bond Street London, David Morris is home to some of the rarest, pure diamonds. Hadcafted into statement high jewellery and scattered through our fine jewellery pieces, we have a selection of white diamonds and coloured diamonds, each one possessing the beauty and originality of a pure natural diamond.
Crafted into wedding jewellery, bespoke designs and magnificent high jewellery pieces, our diamonds are the epitome of luxury.
To discover the world of David Morris diamonds, get in touch with one of our diamond experts or book a consultation at one of our boutiques for our unique experience.
