How Are Diamonds Formed? The Four-Stage Journey, and What It Left Behind in Your Ring
Ask most people how a diamond forms and you get a version of the same sentence: carbon gets squeezed deep in the Earth for billions of years, a volcano brings it up, someone digs it out. That sentence is not wrong. It is just compressed so tightly that it hides the interesting part, and it quietly gets one important detail backwards.
Here is the short answer, stated accurately:
Diamonds form when carbon crystallizes roughly 90 to 125 miles (150 to 200 km) below the Earth's surface, at around 900 to 1,300°C and pressures near 45,000 to 60,000 times atmospheric pressure. The crystals then sit in storage in the deep mantle for a very long time, sometimes billions of years, before a rare and violent kind of volcanic eruption carries them to the surface in a matter of hours.
Notice what that does and does not say. It does not say the growing took billions of years. That distinction is the single most misunderstood thing about diamond formation, and it turns out to matter if you are the person deciding which diamond to buy.
This guide walks the whole journey in four stages, corrects the timeline myth, retires the coal myth properly, and then does something most articles on this topic skip entirely: it shows you how to read a diamond's formation history in the stone sitting in your jewelry box right now. Color, clarity, shape, even why round diamonds are so common, all trace back to what happened underground.
What Are Diamonds Actually Made Of?
One element. Carbon. That is the whole ingredient list.
The same element that makes up pencil graphite, charcoal and the soot on the bottom of a pan is the only thing in a diamond. What separates a diamond from a pencil lead is not the ingredient; it is the architecture.
In graphite, carbon atoms bond into flat sheets that slide over one another, which is exactly why a pencil leaves a mark on paper. In diamond, every carbon atom bonds to four neighbors in a rigid three-dimensional lattice, each atom locked in place from every direction. That geometry is the source of everything a diamond is known for: its hardness, its high refractive index, the way it bends and returns light.
It also explains why diamonds are so intolerant of impurities. The lattice is so tightly packed that very few other elements can squeeze in. Two that can are nitrogen and boron, and as you will see later, those two intruders are responsible for a surprising amount of what you pay for.
If you want a deeper look at what defines a diamond as a material and a symbol, our guide to what a diamond is covers the definition, history and meaning in more depth.
Stage 1: The Ingredients and the Kitchen
Where the carbon comes from
Not all diamond carbon has the same backstory, and gemologists can actually tell the difference.
Some of it is carbon that has been part of the mantle since early in Earth's history. Some of it is recycled surface carbon. The ocean floor carries carbonate minerals and the carbon-rich remains of marine organisms, and where tectonic plates collide, that seafloor gets dragged down into the mantle through subduction. Carbon that once sat at the bottom of an ocean can end up hundreds of kilometers deep.
Researchers separate diamonds into broad families based on the mineral inclusions trapped inside them, which reflect the rock they grew in. Some grew in peridotite, the mantle's default rock. Others grew in eclogite, which is closely tied to that subducted oceanic material. It is a genuinely strange thought: a portion of the world's diamonds contains carbon that was once at the surface of the planet, got buried to extraordinary depth, and came back up as a gemstone.
The specific conditions required
Diamond only forms inside a narrow window of pressure and temperature. Get it wrong in either direction and carbon becomes graphite instead.
| Condition | Approximate range |
|---|---|
| Depth (most gem diamonds) | 90 to 125 miles / 150 to 200 km |
| Temperature | 900 to 1,300°C |
| Pressure | 45 to 60 kilobars, roughly 45,000 to 60,000 times surface atmospheric pressure |
| Age of most dated diamonds | 1 to 3.5 billion years |
Around 98% of natural diamonds come from that 150 to 200 km band. A small and scientifically fascinating group, known as superdeep diamonds, formed far lower, in some cases below 400 km and occasionally as deep as 700 km. Those are rare, and they are the ones that keep researchers up at night, because they carry samples from parts of the planet we can reach no other way.
Why only certain parts of the world
Here is a point that gets skipped constantly, and it explains diamond geography better than anything else.
Those pressure and temperature conditions are not enough on their own. You also need somewhere stable enough to hold the diamond for the long haul. That place is a craton: an ancient, thick, cold, geologically quiet core of continental crust with a deep root of mantle rock beneath it, often called a keel, extending 150 to 200 km down.
Cratons are the oldest and calmest real estate on Earth. Around 18% of the planet's surface sits on one. That keel is cold enough and stable enough for diamond to survive rather than convert to graphite or dissolve, which is why diamonds are associated with specific ancient terrains in southern Africa, Siberia, northwest Australia, Canada and Brazil, rather than being scattered evenly around the globe.
The recipe needs the right ingredients, the right oven, and a very patient pantry.
Stage 2: Growth, and the Timeline Everyone Gets Wrong
This is where nearly every article on this subject, including some written by jewelers, states something that sounds authoritative and is not quite true.
You will read, over and over, that it takes one to three billion years to form a diamond. Read carefully, and you will notice something odd about that claim: how would anyone know?
What scientists actually measure
They do not date the diamond. They cannot. Pure carbon does not carry the radioactive isotope systems that geologists use for dating.
What they date is the tiny mineral inclusions trapped inside the diamond as it grew: garnets, sulfides, clinopyroxenes. Those minerals do contain datable isotopes. So the age reported for a diamond is really the age of the material sealed inside it at a specific moment of growth.
That gives you a timestamp. It does not give you a stopwatch.
Diamonds grow in episodes, not in one long push
When researchers image the internal structure of diamonds using techniques like cathodoluminescence, they see growth zones layered like tree rings. Those layers record separate growth events, and the gaps between them are the interesting part.
In one diamond from the Mir mine in Russia, inclusions in the core and inclusions near the rim differ in age by around one billion years. A diamond from the Letlhakane mine in Botswana showed an even larger gap, roughly two billion years between growth zones.
That is not one continuous process. That is a crystal that grew, then stopped, then sat, sometimes partially dissolved back into the surrounding mantle when passing fluids changed the chemistry, then grew again when conditions returned.
So how long does the growing itself take?
Honestly: nobody knows, and the scientific literature is upfront about it.
Gem-quality diamonds almost never trap the fluids they grew from, so there is no direct record of growth rate. Fast-growing fibrous diamonds do trap those fluids, which is how researchers study the chemistry, but those are not the same as gem crystals.
The most accurate framing available is this:
A diamond's age tells you how long it has existed. It does not tell you how long it took to make. The growth may have happened in bursts far shorter than the age suggests, separated by enormous stretches of doing nothing at all.
That distinction is not pedantry. It reframes what the "billions of years" number is actually describing, and it leads directly to the stage almost nobody writes about.
Stage 3: The Forgotten Stage, Storage
Search "how are diamonds formed", and you will find plenty about growth and plenty about volcanoes. You will find almost nothing about the enormous stretch of time in between, which is where most of a diamond's life is actually spent.
Once a diamond forms, it stays put. It sits in the cratonic keel, at depth, in the dark, at temperature and pressure that keep it stable.
We know this with confidence because of a mismatch in the numbers. Diamonds are routinely dated to one to three billion years old. The kimberlite rock that carried them to the surface is usually far younger, in many cases a few hundred million years old. The diamond is not the same age as its ride. It waited.
For the vast majority of its existence, a diamond does absolutely nothing.
And it is not entirely a quiet wait. Fluids migrate through the mantle over geological time in a process called metasomatism. Those fluids can add new material to a diamond, and they can dissolve parts of it away. Many rough diamonds show rounded, etched or resorbed surfaces, evidence of being partially eaten by their surroundings before they were ever brought upward.
So when someone says a diamond took three billion years to form, the more accurate statement is that it formed in episodes over a long window and then waited, mostly untouched, for an eruption that would not arrive for another billion years or more.
The waiting is the story.
Stage 4: The Ride Up, and Why Speed Was Everything
Diamonds do not migrate to the surface gradually. They get evacuated.
The vehicle is kimberlite, a rare, gas-charged, deep-sourced magma. Occasionally a related rock called lamproite does the job. Kimberlite magma originates below the diamond storage zone, forces its way upward, and tears through the keel, ripping out fragments of mantle rock, including any diamonds in the path. Those diamonds are cargo, not products. The magma did not make them; it collected them on the way past.
As it rises, dissolved gases expand, the magma accelerates, and it punches a near-vertical channel to the surface known as a kimberlite pipe, shaped roughly like a carrot narrowing downward. Estimates of ascent speeds run from around 10 km/hour to well over 100 km/hour, meaning a journey of 150 kilometers or more is completed in hours.
Speed was not incidental. It was the whole ballgame.
At Earth's surface, diamond is not the stable form of carbon. Graphite is. Diamond exists at the surface only because the conversion happens at a rate so negligible that it is meaningless on human timescales, or geological ones. But heat plus time speeds any conversion up. A slow ascent through hot rock would have given the crystals time to degrade toward graphite. The eruption was fast enough that they arrived essentially intact.
Every natural diamond you have ever seen survived a specific geological accident that had to happen quickly.
The rare part is not the recipe
This reframes the scarcity question entirely. Carbon is abundant. The pressure and temperature conditions exist continuously across huge volumes of the mantle. Diamond formation, in geological terms, is not exotic.
What is genuinely rare is the delivery.
Kimberlite eruptions are uncommon, and most of them are not useful. Industry estimates suggest only about 1 in 200 kimberlite pipes contains gem-quality diamonds in quantities worth mining. There have been no kimberlite eruptions in recorded human history. The pipes we mine are ancient, and we are working through a fixed inventory delivered by events that stopped happening long ago.
Diamonds are not scarce because making them is hard. They are scarce because getting them out was.
Are Diamonds Made From Coal?
No. And the reason is more decisive than most explanations give it credit for.
Most versions of this myth-buster say diamonds and coal both contain carbon but form under different conditions. True, but there is a much cleaner argument available, and it is a matter of simple chronology.
Coal is made from land plants. Most diamonds are older than land plants.
Coal forms from accumulated plant matter in swamps and shallow basins near the surface. The oldest significant coal deposits date to roughly 300 to 400 million years ago, following the spread of land vegetation. Most dated diamonds are one to three and a half billion years old. The raw material for coal did not exist yet when the majority of the world's diamonds were crystallizing.
The geometry disagrees too. Coal seams lie in flat, horizontal, sedimentary layers a few hundred meters down. Diamonds arrive in near-vertical igneous pipes from more than a hundred kilometers down. These are not neighbors.
Where did the myth come from? Partly from the fact that both are carbon and both are mined. Mostly, it seems, from popular culture. The image of Superman squeezing a lump of coal into a diamond is a memorable one, and it lodged.
Being fair to it, the myth contains one grain of truth: you can convert almost any carbon source into diamond if you apply enough pressure and heat. Coal simply is not used, because it is full of sulfur, oxygen and nitrogen. Laboratories use purified graphite, which is cleaner and converts more efficiently.
How to Read Formation History in Your Own Diamond
Here is where geology stops being trivia and starts being useful. Nearly everything you notice in a finished diamond is a formation record. Once you know what to look for, a grading report reads a little like a fossil.
Color is a record of what got trapped in the lattice
That rigid carbon lattice is not perfectly pure. Roughly one impurity atom per million lattice atoms is enough to change a diamond's color completely, and different intruders produce different results.
- Nitrogen produces yellow. Nitrogen is by far the most common impurity in natural diamonds, and how those nitrogen atoms are grouped, whether scattered as single atoms or clustered together over time, changes the exact shade.
- Boron produces blue. Boron is rare in the mantle. It is more common in the crust, which is one reason blue diamonds are associated with deep, subduction-linked origins.
- Plastic deformation produces pink, red and brown. No impurity at all in this case. The crystal was physically distorted by stress in the mantle, bending the lattice and changing how it absorbs light. A pink diamond is a stone that was put under strain and kept the mark.
- Radiation exposure produces green. Natural radioactive decay in surrounding rock alters the lattice near the crystal's surface.
- Dense inclusions and graphite produce black. Not a tint but an accumulation of material dark enough to make the stone opaque.
This is why color in a natural diamond is not a manufacturing choice. It is a biography.
If that idea appeals to you, it is worth browsing by color deliberately rather than defaulting to colorless. BESEEN's diamond jewelry collection can be filtered by natural diamond color, including black, blue, green, pink, red, yellow and multicolor, all set in recycled 14K solid gold. A pink or black diamond is not a lesser stone. It is a stone with a more eventful history.
Clarity is a record of the neighborhood
The inclusions inside a diamond are not flaws in the sense of manufacturing defects. They are usually crystals of other minerals that were present in the mantle and got sealed inside as the diamond grew: garnet, olivine, sulfides, sometimes another small diamond.
Those inclusions are precisely what scientists use to date and classify diamonds. The features that lower a clarity grade are the same features that let researchers reconstruct where and when a stone formed. A diamond with no inclusions is easier to grade and harder to study.
Practically speaking, this matters because it separates two things buyers often merge. An inclusion you cannot see without magnification affects the paperwork, not the appearance. An eye-clean stone with an excellent cut will out-sparkle a technically higher-clarity stone that was cut poorly, every time. Our complete guide to the 4Cs breaks down where clarity genuinely matters and where it is worth spending elsewhere.
Crystal shape decided which cuts exist
This one surprises people. The reason round diamonds dominate the market is partly a decision made underground.
When diamonds grow in the mantle, they overwhelmingly form octahedra, two four-sided pyramids joined base to base, like a spinning top. Cubes and dodecahedra occur, and twinned flattened triangular crystals called macles are common, but the octahedron is the default.
An octahedron happens to be an efficient starting point for a round brilliant. A skilled cutter can often produce two round stones from a single octahedral crystal. Even so, cutting a round brilliant from octahedral rough typically sacrifices about 50% of the original weight, and irregular rough can yield far less, sometimes only 20 to 30%.
That waste is why cut diamonds cost what they do, and why fancy shapes exist. A macle is a poor candidate for a round but a natural fit for a pear or a trilliant. Elongated rough suits ovals and marquises. The shapes in a jeweler's case are, in part, a catalogue of the shapes the Earth handed over.
It also explains a design category that puzzles people. Large, clean, well-formed rough is genuinely rare, which is why cutters developed illusion settings that assemble several precisely cut segments into the visual impression of one much larger stone. BESEEN's pie cut collection works on exactly this principle, and it exists because of a geological constraint, not a stylistic whim.
Cleavage is a record you should actually plan around
Diamond is the hardest natural material, a 10 on the Mohs scale. Hardness means resistance to scratching, and nothing scratches a diamond except another diamond.
Hardness is not toughness, and confusing the two causes real damage.
Because of how the lattice is built, diamond has perfect cleavage in four directions along its octahedral planes. Those are planes of relative structural weakness inherited directly from how the crystal formed. Diamond cutters have exploited them for centuries: a correctly placed strike splits a crystal cleanly. The same property means a sharp knock at an unlucky angle can chip a set stone.
The practical takeaway is about setting choice, not anxiety. If a piece is going to be worn daily, on hands, through doorframes and gym bags, protective settings earn their keep. A bezel setting surrounds the stone's girdle with metal. A flush or channel setting sits the diamond into the band rather than raising it. Pavé and station designs distribute many small stones, none of which projects far enough to take a hard hit.
You can see this reasoning in practice across BESEEN's diamond rings, where bezel-set and low-profile designs sit alongside more traditional prong work, and across the diamond bracelets range, where wrist-worn pieces take more incidental contact than almost anything else you own. For everyday earrings, diamond stud designs face far less impact risk than rings do, which is why studs tolerate more exposed settings comfortably.
Which of the 4Cs Did Geology Decide?
A useful way to hold all of this at once. Two of the 4Cs were essentially fixed underground. One is entirely human. One is shared.
| The C | Decided by | What that means for you |
|---|---|---|
| Color | Geology, almost entirely | Trace elements and lattice distortion set at formation. Not a design decision. |
| Clarity | Geology, with human editing | Inclusions were trapped during growth. A cutter can sometimes remove or hide them, at the cost of weight. |
| Carat | Shared | The Earth set the size of the rough. The cutter decides how much to keep versus how well it performs. |
| Cut | Human, entirely | The only C with no geological component. It is also the one that most affects how a diamond looks. |
There is a genuinely useful conclusion buried in that table. The single factor with the largest influence on whether a diamond looks brilliant is the one the Earth had nothing to do with. Formation gave you a raw material with a fixed color, a fixed set of inclusions and a maximum possible size. Everything about how that material catches light was decided by a person with a wheel.
Which is a good argument for prioritizing cut quality over chasing a marginally better color or clarity grade. Our breakdown of what carat weight actually measures goes further into how size and visual impact diverge.
Lab-Grown Diamonds: Same Recipe, Different Kitchen
Since the timeline question inevitably leads here, worth addressing directly and without spin.
A lab-grown diamond is a diamond. Same element, same lattice, same hardness, same optical behavior. It is not a simulant. Cubic zirconia and moissanite are simulants, materials that resemble diamond without being diamond, and the distinction is worth understanding clearly, which our diamond versus cubic zirconia comparison covers in detail.
Two production methods dominate:
HPHT (High Pressure High Temperature) reproduces mantle conditions mechanically, pressing carbon at high pressure and temperature with a metal flux to help it crystallize.
CVD (Chemical Vapor Deposition) takes a different route. A carbon-containing gas is broken down in a vacuum chamber and carbon atoms settle onto a thin diamond seed plate, layer by layer, at much lower pressure.
Growth takes days to weeks depending on size and method, rather than the long geological windows involved underground.
What actually differs is origin, rarity and price, not material quality. A lab diamond is not a compromise on durability or brilliance. A natural diamond is not optically superior. What a natural diamond carries is a specific and unrepeatable history: a particular carbon source, a particular set of mantle minerals sealed inside it, a particular eruption. Whether that history is worth paying for is a personal judgement, and an entirely reasonable one either way.
Where transparency matters is labeling. A piece stamped LG contains a lab-grown stone. Reputable jewelers state origin plainly. Our guide to hallmarks and diamond symbols on jewelry covers how to read these stamps yourself.
BESEEN's 14K solid gold pieces are set with natural diamonds, and the collection is filterable by diamond type so you can see exactly what you are looking at before you buy.
What Any of This Means When You Are Actually Buying
Pulling the geology into decisions you will genuinely make:
Spend on cut before anything else: It is the only C that a human controls, and it is the one that determines how a diamond behaves in light. A well-cut smaller stone beats a poorly cut larger one, visibly, in any lighting.
Treat eye-clean as the practical clarity target: Inclusions are formation records. If you cannot see them without magnification, you are paying for a certificate line, not for appearance.
Consider color as character rather than deviation: Naturally colored diamonds are records of unusual formation conditions. Filtering by color opens up options that colorless-by-default shopping hides entirely.
Match setting to lifestyle, using cleavage as the reason: Hardest does not mean unbreakable. Daily-wear rings benefit from bezel and low-profile settings. This is the single most useful practical fact in this article.
Ask about sourcing and expect a straight answer: Formation happens over geological time. Extraction happens in a specific place under specific labour and environmental conditions. Those are separate questions and both deserve answers. Our post on what a blood diamond is and how the Kimberley Process works explains what the certification does and does not cover.
Look after it properly: A diamond survived a mantle eruption but will still lose its sparkle to hand cream and soap film faster than you would expect. Most stones that look dull are simply dirty. Our guide on how to clean diamond rings at home covers safe methods.
If you are browsing, the pieces that show off a diamond's optical behavior best tend to be those where stones sit where light can reach them from multiple angles: diamond necklaces that move against the collarbone, diamond earrings that catch light with every turn of the head, and eternity bands that carry sparkle continuously around the finger. All BESEEN pieces are made in recycled 14K solid gold rather than plated metal, which matters over time because there is no surface layer to wear through.
The Short Version
A diamond's life has four stages, and the popular account collapses them into one.
Carbon crystallized deep beneath an ancient continent, in a narrow window of pressure and temperature. It grew in episodes, sometimes separated by a billion years of stillness, occasionally dissolving back before growing again. Then it waited, in the dark, for a very long time. And finally a rare eruption of kimberlite tore through the rock and carried it to the surface in a matter of hours, fast enough that it survived the trip.
What arrived carries the record. The color in a pink diamond is stress. The color in a yellow one is nitrogen. The inclusions are fragments of the mantle. The shape it was cut into was constrained by the shape it grew into. The only thing about it that no geology decided is the cut, which is also the thing that most determines how it looks.
Which makes a finished diamond a genuinely unusual object: mostly a record of the Earth, finished by a person, and now sitting on someone's hand.
Explore BESEEN's natural diamond jewelry, crafted in recycled 14K solid gold with no plating and no nickel, and made to be worn every day rather than kept in a box.
FAQs
What are diamonds made of?
Pure carbon, one single element. The difference between a diamond and graphite is not composition but structure. Diamond's carbon atoms bond to four neighbors each in a rigid three-dimensional lattice, while graphite's bond into flat sliding sheets.
How long does it take for a diamond to form?
Nobody knows, and this is the most commonly misstated fact about diamonds. Scientists date the mineral inclusions trapped inside diamonds, not the crystal growth itself. Those dates show most diamonds are one to three and a half billion years old, but age is not the same as growth duration. Evidence from growth zoning shows diamonds grow in separate episodes, sometimes separated by a billion years or more of dormancy, so the actual growth may have been comparatively brief.
How deep underground do diamonds form?
About 90 to 125 miles, or 150 to 200 km, for roughly 98% of natural diamonds. A rare group known as superdeep diamonds formed considerably lower, in some cases below 400 km and occasionally as deep as 700 km.
Are diamonds made from coal?
No. The clearest reason is chronological: coal forms from land plants and dates back roughly 300 to 400 million years, while most diamonds are one to three and a half billion years old. The raw material for coal did not exist yet when most diamonds formed. They also form at completely different depths in completely different rock types.
How do diamonds get to the surface?
Through rare volcanic eruptions of a gas-rich magma called kimberlite, and occasionally lamproite. The magma rises from below the diamond storage zone, tears out diamonds along the way, and reaches the surface in hours through a near-vertical channel called a kimberlite pipe. Speed matters, because a slow ascent would allow diamonds to degrade toward graphite.
Why are diamonds rare if carbon is common?
The formation itself is not the rare part. Carbon is abundant and suitable pressure and temperature conditions exist across large volumes of the mantle. What is rare is the delivery. Kimberlite eruptions are uncommon, only around 1 in 200 pipes contains gem-quality diamonds worth mining, and no kimberlite eruption has occurred in recorded human history.
Where are diamonds found?
Almost exclusively in and around ancient continental cores called cratons, which have deep, cold, stable mantle roots capable of storing diamonds without destroying them. That is why production concentrates in specific ancient terrains in southern Africa, Russia, Canada, Australia and Brazil rather than being distributed evenly worldwide.
Do diamonds still form today?
Almost certainly, yes. Conditions in the deep mantle have not changed. What has effectively stopped is the transport. Without kimberlite eruptions, any diamonds forming now stay where they are, roughly 150 km beyond reach.
What is the oldest diamond ever found?
Dated inclusions in some diamonds return ages of around 3.5 billion years, which makes them among the oldest datable materials accessible on Earth and roughly three-quarters the age of the planet itself.
Does an older diamond sparkle more?
No. Sparkle comes from cut quality, proportions, symmetry and polish, none of which have anything to do with age. A three-billion-year-old stone with mediocre proportions will look flatter than a well-cut stone that formed more recently. Age does not appear on grading reports because it is not a quality factor.
Does formation depth affect a diamond's quality?
Not in any way that shows up in grading. Depth influences the type of inclusions a diamond carries and can be linked to certain rare colors, but standard grading measures cut, color, clarity and carat. A superdeep diamond is scientifically interesting, not automatically more beautiful.
Can you tell where or when your diamond formed?
Not from a standard grading report, which does not include origin or age. Determining those requires specialist research on the mineral inclusions, which is destructive in some cases and not part of commercial grading. Some suppliers do offer documented mine-of-origin provenance separately from grading.
Do colored diamonds form differently?
Not in the fundamental process, but in the details, yes. Yellow comes from nitrogen in the lattice, blue from boron, pink and red from physical distortion of the crystal under stress, green from natural radiation exposure, and black from dense inclusions. Each color reflects a specific formation circumstance, which is why fancy colors are much rarer than colorless stones.
Will your diamond eventually turn into graphite?
No, not in any timeframe that concerns you. Graphite is technically the stable form of carbon at surface conditions, but the conversion rate at room temperature is so close to zero that diamonds billions of years old show no meaningful change. It requires extreme heat to proceed at any noticeable rate.
If diamonds are just carbon, why are they expensive?
Because the price reflects extraction, not ingredients. Diamonds sit in a limited number of ancient pipes, only a small fraction of which are economically viable. Recovery moves enormous volumes of rock for small yields. Then cutting typically destroys about half the rough weight, and skilled cutting and certification add further cost. Buying direct-to-consumer removes traditional retail markup layers, which is where meaningful savings are available rather than in the stone itself.
If lab-grown diamonds are identical, does natural formation matter at all?
Materially, no. The two are the same substance with the same hardness and optical properties. What differs is origin and rarity. A natural diamond carries a specific unrepeatable geological history and the inclusions that record it. Whether that history holds value is a personal judgement, and both choices are entirely legitimate.
Are diamonds the strongest material on Earth?
Diamond is the hardest natural material, rated 10 on the Mohs scale, meaning nothing natural scratches it. Hardness is not the same as toughness. Because of its crystal structure, diamond has perfect cleavage in four directions and can chip if struck sharply at the wrong angle. Several materials are tougher than diamond while being far softer.