Where Do Diamonds Come From and How Are They Formed?

Diamonds come in two different forms, you can either opt for a naturally formed diamond or a lab grown diamond. The main difference between these two types of diamonds is their origin. Each is formed under extreme heat and pressure, a natural diamond is formed deep within the earth's mantle whilst a lab diamond is created in a controlled setting in a laboratory. In this guide we will go into detail about how and where both lab grown and earth diamonds are formed. Take a look at our guide on lab grown diamonds to learn more about these gems and find out whether they could be the perfect gemstone for you.

What Are Diamonds Made Of?

Both lab grown and natural diamonds have the exact same chemical composition as each other. Diamonds are made purely from carbon, and they get their clear sparkle from intense heat and pressure. Interestingly, due to their strength and durability, diamonds are often used in tools such as saws and drills!

How Diamonds Are Made

Natural diamonds are formed within the earth's mantle (around 125 miles deep!) over billions of years. These gemstones require an astonishing amount of heat and pressure to be formed, at around 1600 degrees. This process takes billions of years, and diamonds don’t come out of the earth looking like they do in our jewellery, once they are formed they go through a process of quality assurance and then they are cut into different shapes before being made into jewellery or tools.

How Are Lab Diamonds Made?

While natural diamonds take millions of years to form, lab grown diamonds are created in a matter of weeks. They are produced using the same process of heat and pressure, but this process is accelerated in a laboratory setting. Read our guide on how lab grown diamonds are made to find out more about the detailed formation process of these gems.

How Long Does It Take For a Diamond to Form?

Natural diamonds take millions of years to form, on average these gemstones take 1 to 3.3 billion years to fully develop! 

However, lab-grown diamonds take significantly less time to be created, typically only 8 to 10 weeks. Formed in a laboratory setting, their production allows for much greater control over the conditions and speed of their formation.

Where Are Diamonds Mined?

Diamonds are mined in several countries around the world such as Canada, Australia, Russia, Brazil, Zimbabwe and other African countries. however some nations have more abundant diamond resources and are more renowned for their diamond mining than others.

Which Country Has The Most Diamonds?

Most of the top diamond mining countries are located in African countries as Africa's diamond deposits are overall much higher than in other places around the world. However, there are countries all over the planet that are responsible for high numbers of diamond sourcing, such as Russia (which has more deposits than any singular country in Africa) and Australia! Our diagram below shows the main diamond mining countries:

top 10 diamond mining countries

How Diamonds Are Mined: Step by Step

The mining process for natural diamonds involves several important and complex steps. Here’s an overview of the natural diamond mining process:

1. Analysis

The first step involves geologists surveying and analysing areas where there might be possible diamond deposits. Once the area has been tested for diamond content, the geologists will drill into the earth to confirm that there are in fact diamonds forming in that area.

2. Mining

The second step is either open pit mining, where large pits are dug which reveals the ore from which diamonds can be mined! Or underground mining, meaning tunnels and shafts are dug into the area to reach diamonds which are far deeper within the earth.

3. Extraction

Extraction involves all the mined stone being broken down into smaller pieces, these pieces then go through a screening process to ensure only the right sized pieces make it to the Cyclonic Separation stage. Cyclonic Separation involves using an x-ray fluorescence technology to separate diamonds from other minerals.

4. Collection

There are two ways for collecting the diamonds from among the rest of the minerals. The first method involves what's called a ‘grease table’, where diamonds will stick to the grease while the rest of the minerals wash away once water is poured over them. This is because diamonds are hydrophobic, meaning they repel water!

5. Cleaning and Categorising

At this point the diamonds are cleaned to remove excess dirt and sorted by size, colour and quality.

5. Cutting and Polishing

After they have been sorted into the correct categories, the diamonds are cut into whichever shape will maximise the specific stones value. Rough diamonds are split along their naturally formed lines or sawed into pieces. They then go through a process called bruting, which involves the stone being cut into a rough shape before it's finally polished to maximise its sparkle!

6. Valuation and sale

Once the stone is cut and polished, it will be graded on the 4 Cs, a method used to determine the quality of a stone by measuring its carat, colour, cut and clarity. Take a look at our guide on the 4 Cs if you would like to learn more about how these factors affect a diamond's overall quality. Once the stone has been graded, it will receive a price and will be sold to a manufacturer, jeweller or consumer before being made into a beautiful piece of jewellery.

Book an appointment

Our gemstone experts are here to answer any questions you might have. If you're still looking for answers then don't hesitate to reach out. You can also visit us at our Sheffield showroom or book in for a virtual appointment if you're not local.

The Importance Of Choosing Ethical Diamonds

If you’ve decided that a natural diamond is the one for you, it's extremely important to learn and understand where the stone has come from. This is due to the fact that some diamond mines could be operating using unethical methods, this could include unfair working environments and ill-treatment of miners.

However, the main reason to be vigilant when choosing a natural diamond is to make sure that you don’t purchase a blood diamond. A blood diamond, also known as a conflict diamond, is a stone that has been mined in a war zone and sold illegally as a way to fund terrorist activity or anti-government militia. These diamonds get their name due to the bloodshed that they cause, so it’s very important to ensure that your diamond hasn’t come from one of these sources. Read our natural diamond guide to learn more about blood diamonds and conflict diamonds.

At Jessica Flinn we only work with suppliers we know and trust. We vet them in person where we can to check that their business is trading fairly, and we only work with suppliers who source from conflict-free countries such as the USA, Sri Lanka, Australia and Botswana.

Find The Perfect Diamond With Jessica Flinn

At Jessica Flinn you can feel confident that whatever diamond you choose, whether lab grown or natural, has been acquired in the most ethical way possible. Take a look at our lab grown diamond guide to find out why a lab diamond could be the perfect gemstone for you. Book an appointment today to begin your journey to find your perfect diamond.