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How Far Below the Earth’s Surface Are Most Diamonds Crystallized?

How Far Below the Earth’s Surface Are Most Diamonds Crystallized?

When we talk about diamonds, a question is often asked about their origin, where, and how they are formed: How far below the Earth’s surface are most diamonds crystallized?

The most precise and correct answer would be: Natural diamonds are formed 150-200 kilometers below the earth’s surface.

As a follow-up, we would have to add that diamond formation occurs only below the oldest continents that have been stable for billions of years; these locations are known as cratons.

In this article, we will try to go through everything with you from the beginning, from the origin of diamonds, their value, and much more, so you can understand our answer.

Let’s take a look at what we’ve prepared for you!

Diamonds and Their Properties

Let’s explain in detail what diamonds are, how they are made, and many more!

A gemstone is referred to as a “diamond.” A gemstone differs from a rock because it comprises a single crystallized mineral.

The number of diamonds produced is decreasing as mines close for various reasons. The high marketing cost, scarcity of exceptional grade stones, and strong demand contribute to diamonds’ high price. It all comes down to supply and demand.

The majority of diamonds may be found in kimberlites, pipe-like structures formed by tectonic and volcanic activity.

The second sort of geological source for diamonds is placer deposits.

Diamonds are easily worn out of the kimberlite host rock, in which they are embedded and washed away by rivers and streams. Graphite, much like a diamond, is another solid form of carbon that’s also chemically stable at standard temperature and pressure.

Diamonds are known for their extraordinary hardness, unrivaled brightness, and enormous emotional worth. Although almost wholly constituted of carbon atoms, diamonds are the only other solid that can scratch their surface.

Now that we’ve covered what diamonds are and how they’re made let’s look at their value and worth!

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Diamond Value

The first thing we would like to touch upon is that diamond prices are unique.

Several factors influence their true worth. At least, that’s what jewelers tell you all the time. True, but it doesn’t have to be that complicated.

This article provides the tools to estimate how much a diamond should cost and how much a diamond is worth since, as you are undoubtedly aware, the two are different.

Price and value are not the same things. That is something you should be aware of. So, let us sort out the discrepancies!

You’re probably wondering why diamonds are so pricey. Diamonds are expensive due to their high marketing expenses, scarcity of exceptional grade stones, and strong demand. Only supply and demand will determine the outcome.

Is price related to the diamond mining process? The diamonds are easily extracted from the kimberlite host rock. However, they become entrenched in rivers and streams and are dragged away by them.

Now that we’ve defined a diamond let’s look at how they’re formed!

Diamonds begin as carbon atoms that come together under tremendous pressure and heat to create crystals since they are composed of carbon.

What about their dimensions? Millimeters are used to measure diamond sizes (mm). These measurements are equivalent to carats.

A 1-carat round diamond has a 6.5 mm diameter, whereas a 1.25-carat diamond has a 6.8 mm diameter. A one-carat square-cut diamond, such as a princess or cushion, typically measures 5.5 mm, but a 1.25-carat diamond measures 6 mm.

The diamond output drops as mines near the end of their productive lives.

Related Read: How Long Does A Diamond Take To Form And Grow?

Diamond Formation Methods

Many people think that diamonds are generated as a result of coal metamorphism. This is still the “how diamonds form” myth in many science courses.

Coal has rarely been involved in the creation of diamonds. Most dated diamonds are substantially older than Earth’s earliest land plants – the primary material of coal!

That alone should be enough to disprove the theory that coal produced the Earth’s most expensive stones – diamonds.

Another flaw in the concept is that coal seams are sedimentary rocks that often occur as horizontal or nearly horizontal rock groups.

However, diamond source rocks are vertical pipelines packed with igneous materials. Almost all natural diamonds discovered at or near the Earth’s surface are assumed to result from four processes.

One of these techniques accounts for approximately all of the diamonds ever mined. The remaining three are modest commercial diamond sources.

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How Far Below the Earth’s Surface Are Most Diamonds Crystallized?

Geologists think that the diamonds in all commercial diamond resources on Earth were produced in the mantle and transported to the surface by deep-source volcanic eruptions.

These eruptions create the kimberlite and lamproite pipes that diamond prospectors seek.

Most of these pipes are either diamond-free or contain such a small amount of diamond that they are not commercially viable.

However, open-pit and underground mines are built when these pipelines contain enough diamonds for economical mining.

Some of these pipelines have also worn and corroded diamonds.

Diamonds are now found in sedimentary (placer) deposits along streams and coasts. Natural diamonds require incredibly high temperatures and pressures to create.

These circumstances exist in a few areas of the Earth’s mantle that are 90 miles (150 kilometers) or more below the surface and have temperatures of at least 2000 degrees Fahrenheit (1050 degrees Celsius).

The crucial temperature-pressure condition required for diamond creation and stability does not exist globally. It is instead considered to exist predominantly in the mantle underneath the stable interiors of continental plates.

During deep-source volcanic eruptions, diamonds generated and preserved in these “diamond stability zones” are brought to the Earth’s surface. These eruptions rip apart the mantle and swiftly transport it to the surface.

This volcanic explosion is unusual, and modern people have never witnessed one.

Is coal a factor? Coal is a sedimentary rock from plant waste accumulated on the Earth’s surface. It is seldom buried deeper than two miles (3.2 kilometers).

Coal being transferred from the crust to a depth much below the base of a continental plate is highly implausible.

Carbon locked in Earth’s interior during the planet’s creation or carried to extreme depths by subduction is most likely the carbon source for these mantle diamonds.

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The Formation of Diamonds on the Earth’s Surface

On Earth’s surface, people identified new ways of diamond creation in the 1950s. Scientists could generate the temperature and pressure conditions required to make diamonds in a lab.

Although most early diamonds were not of gem grade, they were ideal for use as abrasive grains in drill bits, cutting tools, and grinding wheels.

Larger lab-grown diamonds were soon being produced for use as wear-resistant bearings, computer processor heat sinks, and high-temperature windows.

Almost all diamonds used in industrial operations today are lab-created.

They are also produced sufficiently to receive colorless and faintly included grades from diamond grading laboratories.

They are colored by adding nitrogen (yellow) or boron (blue) to the diamond-forming environment. Post-growth treatment methods can produce green, pink, orange, and other hues.

Diamonds generated in a laboratory are produced in the United States and numerous other nations. China is the world’s biggest producer of lab-created diamonds.

All lab-grown diamonds are created with equipment that uses massive amounts of power to generate the temperature and pressure conditions required to grow diamonds.

Some of the power will undoubtedly be generated by coal combustion.

So far so good! Let’s move on to our next question – How deep do diamonds go in the earth?

How Deep Are Diamonds Located On The Earth?

Natural diamonds form 150-200 kilometers below the earth’s surface.

Diamond formation occurs only below the oldest continents that have been stable for billions of years; these locations are known as cratons.

How do you know whether there is a diamond in the ground? Here are some pointers to help you identify a genuine diamond:

  1. Examine their inherent radiance.
  2. Diamonds are bright.
  3. Diamonds are rounded rather than edgy.
  4. Examine the transparency.
  5. Examine the toughness.

Learn More: Diamond History: How They Form And How They’re Found


Let us help you with these frankly asked questions!

1. Is It Possible to Locate a Diamond In My Backyard?

Diamonds may be found in your backyard, primarily if you reside in areas of the United States where the historic volcanic activity occurred. You can also find diamonds in stream beds on your land.

Related Read: What Happens If You Find Diamonds On Your Property?

2. Is it Possible To Find Diamonds On The Surface?

Most surface diamonds are discovered on sunny days, two to three days following rainfall. Allowing time for the earth to dry enhances the metallic sheen of the diamond against dark diamond-bearing soil.

After day three, the odds of discovering a diamond on the surface rapidly decrease.

3. How Long Does it Take to Make a Diamond?

A diamond eventually begins to develop due to the high pressure present in this section of the earth and the intense temperatures.

The entire process of diamond formatting takes between 1 billion and 3.3 billion years – around 25% to 75% of the age of our planet.

4. Where Can You Find The Most Diamonds?

Diamonds may be discovered in over 30 countries; however, the top diamond producers are:

  1. Russia.
  2. Botswana.
  3. Canada.
  4. Angola.
  5. Southern Africa
  6. The Democratic Republic of the Congo
  7. Namibia.

Learn More: Top Diamond Producers: Which Region Specializes in Diamonds?

5. How Can You Know Whether a Stone Is a Diamond?

Scratching corundum is the sole hardness test that will identify a diamond. Corundum, which comprises all rubies and sapphires, has a toughness rating of 9.

You’ve probably found a diamond if your suspected diamond crystal can scratch corundum.

6. What Kind of Soil Do Diamonds Grow In?

Pipes of the minerals kimberlite and lamproite are frequently found in the Earth’s upper mantle, and their pipe “trails” include diamond crystals.

These minerals are weather resistant and denser than quartz sand.

7. What Type of Rock Does Diamond Occur In?

Diamond can only form under extreme pressures. Kimberlite, an ultrabasic volcanic rock created deep inside the Earth’s crust, contains it.

The tremendous pressures required to create diamonds can only be found at depths more than 150 kilometers.

8. What Type of Rock Transforms Into Diamonds?

Kimberlite, an igneous rock associated with diamonds, develops deep inside the Earth’s mantle and is driven to the surface by volcanic eruptions.

The rock is subjected to the intense conditions required to make the sought diamonds during this quick and violent procedure.

9. Is There Any Value In Raw Diamonds?

Raw diamonds with few standard inclusions are more valuable than diamonds with multiple common defects. A rough diamond with a brownish or yellowish tinge is more powerful but less expensive.

Diamonds with less color, on the other hand, are significantly more valuable. Transparent and colorless diamonds are scarce.

Learn More: Are Raw Uncut Diamonds Worth Anything?

Final Thoughts

When we talk about diamonds, one of the most frequently asked questions is their origin, where they develop, and how they are formed aka: How far below the Earth’s surface are most diamonds crystallized?

According to the most accurate and correct response, natural diamonds form 150-200 kilometers below the earth’s surface.

As a follow-up, we had pointed out that diamond creation happens only beneath the oldest continents that have remained stable for billions of years; these regions are known as cratons.

We hope that in addition to the answer to the original question, you learned a lot of new things and received a response to perhaps a few more questions that have been bothering you.

Also, we hope you’ve enjoyed reading this article as much as we have while writing it!