What Are Diamonds Made Of? | We Revealed Astonishing Facts About These Valuable Stones!

Diamonds, considered often synonymous with elegance and luxury, have captivated human beings for centuries above even other striking jewels. These dazzling gemstones, with their unparalleled brilliance and purity, hold a special place in modern culture from being marriage symbols to other gifts of love. But how exactly are diamonds made? What are they made of?

In this article, we will dive into the science behind these exquisite gems. Natural diamonds are formed deep beneath the Earth’s surface under intense pressure and temperature conditions. Made solely of carbon, they possess exceptional chemical purity that sets them apart from other, much more brittle, carbon minerals like graphite. 

Join us as we explore the fascinating world of diamonds and unravel the mysteries that lie in their formation.

Key Takeaways

  • Diamonds are made of primarily a single element, carbon, typically about 99.95%.
  • The elements that make up the other .05% can influence the color and crystal shape of diamonds.
  • Diamond forms under high temperature and pressure conditions

How Are Diamonds Made?

Diamonds are made of carbon, with a typical purity of about 99.95%. They are formed under high temperature and pressure conditions at specific depths below the Earth’s surface, around 200 kilometers.

Despite common misconceptions, diamonds are not made from coal; they have a different chemical composition and formation process.

What Are Diamonds Made Of?

Composed solely of carbon atoms, diamonds possess a unique structure that contributes to their exceptional hardness and transparency. The structure of a diamond consists of carbon atoms arranged in a crystal lattice, which is what makes this jewel so strong 

Here are four key characteristics of what diamonds are made of:

  1. Purity: Diamonds have an extremely high level of chemical purity (again, 99.95% carbon), with minimal impurities or trace elements present.
  2. Crystalline Form: Diamonds have an isometric crystal structure, which means they have perfect symmetry and uniformity in all directions unlike other gems such as emeralds.
  3. Octahedral Shape: Most rough gem-quality diamonds naturally form as octahedrons, which are eight-sided polyhedrons with triangular faces, but a small number of diamonds can be other shapes
  4. Color Variation: While the chemical composition remains the same for all diamonds, trace elements can influence their coloration, ranging from colorless to various shades like yellow, blue, or pink.

Understanding what diamonds are made of lays the foundation for exploring how they are formed deep beneath the Earth’s surface through intense pressure and heat processes in diamond mines.

A diamond closeup

How Are Diamonds Formed?

Diamonds are formed deep within the Earth’s mantle under high temperature and pressure conditions. When there is more pressure there can be less heat and vice versa.

For example, diamonds can form during subduction, where carbonate rocks are subjected to extreme pressure about 50 miles below the Earth’s surface. In this process, there isn’t as much heat but much more pressure from the shifting of tectonic plates.

The formation process makes carbon atoms bond differently than other materials to create the unique structure of a diamond.

Additionally, diamonds can be found at space object impact sites due to the intense pressure and temperatures caused by high-speed collisions in space.

The time it takes for diamonds to form can range from days to millions of years, depending on the specific geological conditions.

Formation in Earth’s Mantle

Diamonds can also be formed in the Earth’s mantle, where they undergo their remarkable transformation. Some more notes about the formation process in the mantle:

  • Carbon deposits go through high pressure and temperature conditions.
  • This leads to the formation of diamonds, which can have unique properties depending on a number of other factors
  • The process typically occurs at depths of around 200 kilometers below the Earth’s surface.

Now let’s explore how diamonds are formed in subduction zones.

Images of rough diamonds

Formation in Subduction Zones

Subduction zones, where rocks are pushed and then return to the surface, offer a unique environment for the formation of small, rough, and primarily undesirable diamonds. These diamonds form around 50 miles below the Earth’s crust at temperatures as low as 390 degrees Fahrenheit. Although no commercial diamonds have been found within subduction zones because they are of low quality, some stones from these areas contain traces of oceanic crust and appear as blue diamonds. 

Formation at Impact Sites

At impact sites, the intense pressure and temperatures generated by asteroid collisions create a unique environment that facilitates the formation of diamonds. These conditions are ideal for transforming carbon into the hardest mineral on Earth similar to the environment that diamonds are made in under the Earth’s surface.

How Long Does it Take For Diamonds to Form?

The duration required for the formation of diamonds is not actually clear. In fact, it is a matter of significant debate and uncertainty among geologists and scientists alike. 

Some researchers propose that diamonds can form in a matter of days, while other scientists argue that the process may take up to dozens of years. The slow growth rate of diamonds suggests that their formation occurs over long periods, possibly spanning centuries. However, it is commonly accepted that different methods and locations of where diamonds are formed can cause the formation times to vary. 

A diamond closeup

Are Diamonds Made From Coal?

Contrary to the popular saying and many song lyrics, diamonds are not made from coal. While both diamonds and coal are composed primarily of carbon, the formation processes and conditions differ significantly.

Diamonds are formed deep within the Earth’s mantle under extreme pressure and temperature conditions, most commonly around 200 kilometers below the surface. The carbon atoms in diamonds bond differently from other elements due to these high pressures, resulting in their unique crystal structure and exceptional hardness.

On the other hand, coal forms from ancient plant material that undergoes partial decomposition over millions of years. Although both substances contain carbon, their chemical composition and geological origins distinguish them from each other significantly. Understanding this distinction is crucial in dispelling the misconception that diamonds are derived from coal.

Where Are Diamonds Found?

Natural diamonds are primarily found in special volcanic formations called Kimberlites, which are typically located around 200 kilometers beneath the Earth’s surface.

The process of extracting diamonds from these deep underground deposits can cause extreme environmental damage and disruption to ecosystems as they displace thousands of tons of the earth.

Given the detrimental impact of diamond mining on the environment, there is a constant debate about whether natural diamonds can be considered environmentally friendly or sustainable.

Are Mined Diamonds Good for the Environment?

Mined diamonds raise concerns regarding their environmental impact. This is because the process of extracting them from the Earth can cause significant damage to ecosystems and contribute to deforestation, soil erosion, and water pollution.

Large areas of land are usually cleared for diamond mining operations, leading to the destruction of many habitats and loss of biodiversity. Additionally, mining activities can contaminate nearby water sources with toxic chemicals used in the extraction process, poisoning the nearby land.

Moreover, diamond mining requires substantial energy consumption and emits greenhouse gases, which contribute to climate change. The negative environmental impacts associated with mined diamonds have led many consumers to seek alternative options such as lab-grown diamonds. 

Diamond mines and kimberlite images

About Lab Diamonds

Unlike natural diamonds, lab-grown diamonds are created most commonly through the High-Pressure High Temperature (HPHT) and Chemical Vapor Deposition (CVD) methods. These two popular methods mimic the natural formation of diamonds but accelerate the process significantly.

How Are Lab-Grown Diamonds Made?

Lab-grown diamonds are primarily created through a process that involves either extreme pressure and heat (HPHT) or a special deposition (CVD). . 

Lab-grown diamonds have the same physical characteristics as naturally mined diamonds. They possess the same hardness, transparency, brilliance, and durability. In fact, they are so similar to natural diamonds that even professional gemological equipment cannot differentiate between them without extensive scientific testing using specialized equipment.

There are some benefits to buying lab diamonds instead of natural ones. Lab created diamonds offer an excellent choice for your earrings and other jewelry pieces if you want a more budget-friendly alternative to diamonds. Here are some of the top benefits:

  • Ethically Sourced
  • Environmentally Friendly
  • Affordable Option
  • Same Quality as Mined Diamonds

Lab-grown diamonds provide an ethical and sustainable choice for consumers who may want to avoid the social and environmental controversy of natural diamonds. Moving forward, let’s explore how long it takes to make a lab diamond

How Long Does It Take To Make a Lab Diamond?

The production process of lab-grown diamonds involves a few steps, with the duration depending on various factors. Generally, lab diamonds can take between 2 and 4 weeks to form. However, this timeline can be expedited by introducing other elements such as nitrogen, although it may result in a yellow tint resulting in less desirable diamonds.

Now let’s explore whether lab diamonds are considered real diamonds or not.

A person checking the quality of a diamond

Are Lab Diamonds Real Diamonds?

Many people question whether lab diamonds are real diamonds. After all, there is a stigma surrounding lab diamonds given that they are cheaper. However, this stigma is promoted by natural diamond companies, which want to control the diamond market.

Authenticity is a defining characteristic of lab-grown diamonds, as they possess the same chemical composition and crystal structure as natural diamonds. Lab diamonds are indistinguishable from their natural counterparts, even to the most specialized laboratory equipment so yes, lab diamonds are indeed real diamonds. 

Now that you know lab diamonds are real, we’ll help you learn about synthetic diamonds.

What Are Synthetic Diamonds?

Synthetic diamonds are the exact same thing as lab diamonds – there is no difference.

The introduction of synthetic gems on the market and their availability in big diamond retail stores like James Allen or Brilliant Earth has changed the diamond industry. Special spectroscopic devices and techniques have been developed to distinguish between synthetic and natural diamonds since natural diamonds are much more valuable. 

While synthetic and lab diamonds may be the same, simulated diamonds are different.

What Are Simulated Diamonds?

Shiny diamonds on the dark background

Simulated diamonds, also known as diamond simulants, are gemstones that are manufactured to imitate the appearance of natural diamonds. Unlike synthetic diamonds, simulated diamonds do not possess the same chemical and physical properties as real diamonds.

Common examples of simulated diamonds include cubic zirconia (CZ) and moissanite diamonds. Simulants can be easily distinguished from natural or lab-grown diamonds by their fiery sparkle when observed with the naked eye. Simulated diamonds are a popular alternative to real diamonds due to their lower price point.

However, it is important to note that simulated diamonds should not be confused with conflict diamonds, which are mined in war zones and sold to finance armed conflicts against governments.

Now let’s explore where natural diamonds are found and how they are extracted from the earth’s depths.

How Hard Is a Diamond?

Renowned for its remarkable hardness, a diamond’s resistance to scratching is unparalleled among natural materials due to its purity, crystalline perfection, and orientation because of the special process that the carbon undergoes to create a diamond. The hardness of a diamond is determined by factors such as its level of purity, the perfection of its crystal structure, and the orientation of its atoms. 

To better understand the hardness of diamonds, let’s consider a comparison between diamonds and other materials on the Mohs scale, with the higher the number representing the harder the object is, with the highest number being 10:

ObjectMOHS Hardness
Orthoclase Feldspar6
Corundum (Ruby/Sapphire)9

As we can see from this table, diamonds have a Mohs hardness rating of 10, making them significantly harder than any other most other occurring material and are more than 4x the hardness of Corundum, which is a 9. In fact, only another diamond can scratch a diamond. This exceptional hardness contributes to its suitability as a gemstone that can withstand daily wear without losing its polish.

The formation process also influences the hardness of diamonds. Natural diamonds often exhibit multiple growth stages, resulting in inclusions in diamonds and defect planes that affect their overall hardness and can be less hard than a perfect diamond. 

With lab diamonds it is fairly easy to consistently create perfect diamonds.

Overall, the exceptional hardness of diamonds sets them apart from other gemstones and makes them highly valued for their durability and resistance to scratching.

A diamond with a note

Frequently Asked Questions

What are the different colors that diamonds can come in?

Diamonds can come in a TON of different colors, including white, yellow, brown, blue, green, and pink. These colors are caused by the presence of trace elements (elements that are barely there) or structural defects within the diamond’s crystal lattice.

How long does it take for a diamond to form under the earth’s surface?

The time it takes for a diamond to form beneath the earth’s surface varies and is the subject of much, but it can range from days  to hundreds of years. Factors such as temperature, pressure, and availability of carbon contribute to the formation process. Also, where a diamond is created can contribute to how long it takes.

Can diamonds be found in places other than Kimberlite volcanoes?

Diamonds are typically found in Kimberlite volcanoes, but they can also be found in other locations such as in the subduction zone of the Earth, and at asteroid impact sites. 

What are the environmental impacts of diamond mining?

Diamond mining typically has significant environmental impacts. It involves extensive land disturbance, deforestation, and soil erosion. Mining also results in water pollution, habitat destruction, and the release of greenhouse gases which often destroy the surrounding area. Additionally, diamond mines often have negative social impacts on local communities. In extreme cases they are called blood diamonds, when “blood” is spilt to get the diamonds.

How are lab-grown diamonds different from natural diamonds in terms of their chemical composition?

Lab-grown diamonds do not differ at all from natural diamonds in terms of their chemical composition. 

Clear diamonds on the black background


In conclusion, diamonds are  remarkable gems that captivate us with their brilliance and beauty. Often formed deep within the Earth’s crust under intense pressure and temperature, diamonds are composed primarily solely of carbon, making them exceptionally pure. 

Their unique crystal structure gives them their distinct shape and adamantine luster. However, the environmental impact of natural diamond mining is a big concern. 

Fortunately, advancements in material science have made it possible to grow diamonds in laboratories, offering a more sustainable alternative and at a much more affordable price. Like the transformation of a rough, newly found diamond into polished and cut perfection, this innovation shines a light on our ability to create beauty while minimizing harm to our planet.

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