The allure of diamonds has made them the centrepiece of diamond rings. It is not only their brilliance that contributes to their appeal for meaningful jewellery, but also their intriguing formation process.
Diamond formation, whether deep within the earth or in a laboratory, is a remarkable process. From a simple carbon atom to a glittering gem, each diamond is a testament to time, nature, and human ingenuity.
In this blog, we explore how are diamonds formed, what they are made of, and where they are found. We also look at how lab-grown diamonds are made.
Diamonds are made in the Earth’s mantle, approximately 150 kilometres below the surface. Diamonds form in temperatures between an astounding 900 to 1,300 degrees Celsius. They also require intense pressure of between 40 to 60 kilobars (kB).
This immense heat and pressure cause each carbon atom to bond with four other carbon atoms, creating a tetrahedral unit. These units then link together, forming a diamond. This process can take between 1 billion to 3.3 billion years.
A fascinating variation from Earth diamonds is extra-terrestrial diamonds. These celestial diamonds form under high-pressure environments, often resulting from meteorite impacts.
While diamonds do not rain from the sky as it does on Uranus and Neptune, it is still a remarkable journey from the depths of the Earth to your diamond jewellery.
Diamonds, in their most fundamental form, are pure carbon. Their unique carbon arrangement sets them apart from other forms of carbon, such as graphite or coal.
Each carbon atom within a diamond is bonded tightly to four others, creating a sturdy three-dimensional lattice. This unique structure is the reason behind diamonds’ exceptional hardness, ranking them highest on the Mohs hardness scale.
This lattice structure of the carbon results in a diamond's refractive properties. As light enters and interacts with this lattice, it produces a dazzling display of brilliance. The enchanting sparkle of a diamond is a result of a mesmerising interplay between atomic structure and light.
Diamonds are found across several regions worldwide, including Russia, Botswana, and South Africa. The geological conditions in these areas provide the right blend of pressure and heat over a long timescale for diamond formation.
Volcanic eruptions bring diamonds to the surface. These eruptions carve out vertical channels, or 'pipes'. These pipes cool and solidify, leaving behind kimberlite deposits rich in diamonds.
The diamond deposits can be found either in their original pipe formations or known as primary deposits. They can also be washed away by rivers and end up in new locations, referred to as alluvial or secondary deposits.
The discovery of these deposits has led to the creation of diamond mines. Mines are where the extraction of these precious gemstones takes place. There are two main methods of mining diamonds: open-pit mining and underground mining.
In open-pit mining, the surface ground is removed to access the kimberlite rock. Once the ore is accessed, it is broken up and transported for processing.
Underground mining is used when diamonds are situated too deep to be accessed by open-pit mining. In this method, tunnels are dug to reach the kimberlite ore, which is then cut and brought to the surface for processing.
Both methods require a substantial amount of resources and have significant environmental impacts. As a result, the diamond mining industry is facing increasing pressure to reduce its footprint and adopt more sustainable practices.
Not all found diamonds are suitable for use in diamond engagement rings or other jewellery. Only a small fraction of unearthed diamonds meet the quality standards necessary for use in the jewellery industry. The rest find their way into various industrial applications.
Moving from naturally occurring diamonds, we turn our focus to the marvels of scientific advancement – lab-grown diamonds. While man-made, these diamonds share identical physical and chemical properties with naturally formed diamonds.
The process of creating lab-grown diamonds involves simulating the conditions under which natural diamonds form. This simulation is carried out through High Pressure-High Temperature (HPHT) or Chemical Vapour Deposition (CVD) methods. Each method begins with a tiny diamond seed and ends with a full-grown diamond.
Unlike their natural counterparts, lab-grown diamonds take a remarkably shorter period to form. Using HPHT or CVD methods, a diamond seed can develop into a full-sized gem in a matter of weeks. This expedited formation time is a testament to the efficiency of human innovation and technology.
The rise in popularity of lab-grown diamonds is largely driven by their ethical attributes. These diamonds avoid the risk of blood diamonds, aligning with the values of conscious consumers.
With Marlow’s Diamonds, you do not need to wait billions of years for your diamond. We have an extensive variety of natural and lab-grown diamonds ready for your special diamond jewellery.
Some of the most common Q&A's
Diamonds are formed from carbon and not coal. While coal is a carbon-rich material, it is not involved in the formation of diamonds. This is primarily due to the depth at which diamonds form, which is much greater than where most coal deposits are found.
The formation of diamonds can take between 1 billion to 3.3 billion years. This extensive timeframe is due to the specific conditions needed for a diamond to form. A combination of intense heat, high pressure, and the slow building process of carbon atoms all play a part in this prolonged formation.
