8 interesting facts about diamonds


Diamonds: billions of years old, hardest substance on Earth, formed deep underground. Linked to gods and love. Mined globally. Diamond planet discovered in 2004. Explore our buying guide for insights.

Diamond facts

Interested in purchasing diamond jewellery? Or simply want to know more information on diamonds and how they are formed? Our 8 interesting facts about diamonds below are the perfect starting point – detailing historic connotations surrounding diamonds, properties of a diamond and even scientific discoveries of ‘diamond planets’!

1. Billions of years old

Diamonds are billions of years old, and some can even span back to being over 3 billion years old. The Earth itself is estimated to be around 4.5 billion years old – whereas the oldest diamonds are believed to have been crystalised around 3.3. billion years ago. 

2. Hardest substance on Earth

Diamonds are, in fact, the hardest substance on this Earth. They are so hard that the only substance able to scratch or mark a diamond is another diamond. Diamonds are also extremely durable and resilient with a melting point of 3547℃ and a boiling point of 4827℃. 

3. Roman and Greek history

Historically, the Ancient Romans and Greeks initially believed that diamonds were teardrops from the Gods, or splinters from falling or shooting stars. With this belief in mind, Romans then deduced that Cupid’s arrows were tipped with diamonds – this could have been the first association between romantic love and diamonds.

4. Formed 120 miles underground

Diamonds are formed in between 90 – 120 miles beneath the Earth’s surface, and are then carried to the surface during deep volcanic eruptions. 

5. Nearly 100% carbon

Made up of a single element, diamonds are nearly 100% carbon. Under the immense heat and pressure that exists so far down into the Earth’s crust, the carbon atoms bond in a unique way – which then result in the creations of diamonds. However, this process has been exactly replicated to create lab grown diamonds – learn more about the difference between lab diamonds and natural diamonds from our guide.

6. Countries with the main sources of diamonds

The countries that are the main sources of diamonds have fluctuated over the years, beginning in India in the 1400s, when Indian diamonds began to be sold in Venice and other European trade centres. In the 1600s, the diamond supplies in India dwindled – and the main source become Brazil until the late 1800s, when South Africa took over. However, today, there are diamonds mined in many parts of the world.

7. The first engagement ring

History suggests that the first known use of a diamond engagement ring was in 1477. This was when Archduke Maximillian of Austria gave Mary of Burgundy a gold ring – which had an ‘M’ for Mary spelled out using diamonds. 

8. Diamond planet?

In 2004, scientists discovered a planet which they believe is made up of one-third pure diamond – and this planet is believed to be composed of mostly carbon. The planet is found to orbit a nearby star in the Milky Way. 

Those are some cool and interesting facts about diamonds that we find particularly noteworthy, but if you want to research more information on diamonds, our diamond buying guide should be your first port of call. Learn about the 4C’s, diamond certification and how to buy a diamond ring from Shining Diamonds now.