Topaz vs Diamond – The Similarities and Differences (With Photos)

By Dr. Keith Jackson - Geology PhD

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Topaz vs Diamond – The Similarities and Differences (With Photos)

By Dr. Keith Jackson - Geology PhD


Two of the most well-known treasures in the world of sparkling gemstones are topaz and diamond. To some, they might even look similar at first glance. So in this article, we’re diving into the fascinating topic of comparing topaz vs diamond.

Both of them are admired for their beauty and have captured the hearts of many. While they share a sparkle that can light up any room, there’s so much more beneath the surface.

We’re going on a journey to discover the qualities that these gemstones share. We’ll also explore what makes them special and uncover the differences between topaz and diamond.

Whether you’re drawn to the warm hues of topaz or the unmatched hardness of diamonds, there’s no denying the allure of these gemstones. By the end, you’ll have a deeper understanding of these treasures and maybe even find a new favorite!

The Major Differences

Did you know that, in comparing diamond vs topaz, you’ll find that they have more differences than similarities between them? Even in the case of rocks and minerals, beauty comes in different forms and qualities.

Color – Topaz can display a wider range of colors.

A doubly-terminated crystal of sherry topaz
Double-terminated sherry topaz photo provided by and available for purchase at hoorainminerals

Topaz can be a bunch of different colors. It might be blue like the sky, yellow like the sun, or even pink like cotton candy. Sometimes, it even doesn’t have any color at all and looks clear.

This is because different things inside the topaz change its color. So, if you find one, it could be almost any color.

Diamonds, on the other hand, are famous for being clear and sparkly, like a drop of morning dew. But it can surprise you too! They can be yellow, brown, or even blue and pink, but these colors are pretty rare.

Its color comes from tiny bits of other stuff that got mixed in when the diamond was forming.

Even though both topaz and diamond can have awesome colors, the way they get their colors can also differ. Sometimes people change the color of topaz on purpose to make it look different. Diamonds mostly get their colors naturally.

Luster – Diamond is much more brilliant and sparkling.

A 1.13-carat raw diamond with a golden lime color
Golden lime diamond photo provided by The Raw Stone

One of the first things you notice when you look at gems is how they shine and sparkle. This shine is called luster.

Topaz has a vitreous luster, which means it looks like glass, with a bright and shiny surface that catches the light nicely.

Imagine looking through a clean window on a sunny day; that’s the kind of sparkle topaz has. It’s pretty and makes the gem look elegant and smooth.

Diamonds, on the other hand, are in a league of their own. They have an adamantine luster, which is the fanciest and most sparkly kind of shine you can find in gems. This makes it look super brilliant and fiery like they have tiny stars inside them.

When light hits a diamond, it bounces around and comes back out in all the colors of the rainbow. This special sparkle is one of the reasons it’s so loved and why it often catches people’s eyes.

Crystal Structure – Topaz has orthorhombic crystals.

A gorgeous single crystals of lustrous Imperial topaz
Imperial topaz photo provided by Saphira Minerals

If we zoom in really close to topaz and diamond, we can see they’re made up of tiny building blocks arranged in different patterns. This arrangement is what we call the crystal structure.

Topaz has an orthorhombic system. Picture a bunch of boxes, each one a little longer or shorter than the other. And then, stack them all up in a pattern. This is how its crystals are arranged.

Because of this, topaz crystals can be long and skinny or short and fat, but always with flat, straight sides.

Diamonds, meanwhile, have a cubic crystal structure. Imagine taking a bunch of perfect cubes, like dice, and stacking them up in the most even, balanced way possible. Every side is the same distance from the next

This crystal structure makes a shape that’s super strong and can bounce light around like a mini disco ball. It’s what gives diamonds their famous sparkle and makes them the hardest mineral.

Composition – Diamond is made entirely of carbon.

A shiny faceted black diamond that's cut in a pear shape
Pear-shaped black diamond photo provided by Gems House

Just like snacks are made from different ingredients, rocks and gems are made from different stuff too. Topaz and diamond might both be dazzling and used in jewelry, but they have different recipes.

Topaz is made of a special blend that includes aluminum, silicon, oxygen, fluorine, and sometimes hydrogen.

This mix is why it can come in so many colors, from blue to pink to yellow. It’s like how adding different flavors to a cake mix can give you chocolate, vanilla, or strawberry cakes.

Now, diamonds are a whole different story. Imagine if you could make a cake out of just one ingredient, like pure sugar. Diamonds are like that, but instead of sugar, they’re made entirely of carbon.

This carbon-only recipe is why most diamonds look clear or colorless, though some can pick up colors like yellow or blue if there’s a little something extra mixed in.

Formation – Topaz forms in igneous rocks and in cavities of volcanic rocks.

A sherry topaz with a thin black pseudobrookite
Topaz and pseudobrookite photo provided by Mineral Masterpiece

Topaz and diamond are like two very different dishes made from unique ingredients and cooking methods.

Topaz starts its journey deep within the Earth. It’s formed from hot fluids or gases filled with different minerals. These ingredients come from magma, which cools down in cracks and crevices of rocks. This is where topaz begins to crystalize.

This gem can be found in lots of places, hanging out in granite or old, hardened lava flows.

Diamond, on the other hand, has a more dramatic start. It’s born way deeper in the Earth, under higher pressure and heat. When carbon is put under extreme pressure and cooked at incredibly high temperatures, it transforms into diamond.

This process takes billions of years. After they’re formed, a volcanic eruption brings the diamond closer to the Earth’s surface. This is where it can be found, in kimberlite, a special kind of rock that was created by these eruptions.

Density – Diamond is denser.

A gorgeous yellow diamond from Africa
Yellow diamond photo provided by @finemineralphotography

Have you ever wondered why some rocks feel heavier than others of the same size? It’s all about density, which is how much stuff is packed into a certain space.

Imagine you have two backpacks that are exactly the same size, but one is filled with feathers and the other is filled with books. The one with books is going to be a lot heavier, right? That’s because books are denser than feathers.

Topaz and diamond might look similar on the outside, but inside, they’re as different as feathers and books.

Topaz has a lower density. If you had a chunk of topaz and a chunk of diamond that were the same size, the topaz would be a bit lighter.

Diamond, on the other hand, packs its atoms really tightly together, making it denser. This tight packing not only makes it heavier but also helps make it the super tough and sparkly gems we love.

Hardness – Topaz is softer.

A light blue topaz with a wedge crystal structure
Blue topaz photo provided by Collector’s Edge Minerals – @collectorsedgeminerals

Hardness is all about how well a gem can scratch things or avoid getting scratched itself.

Diamond is the ultimate champion of hardness. It’s the hardest natural material found on Earth. This means that nothing else can scratch a diamond except another diamond.

This comes in handy not just for looking pretty but also for cutting through almost anything, which is why it’s used in lots of tools, especially for cutting and drilling.

Topaz is also pretty tough, but it’s not in the same league as diamonds. It ranks an 8 on the Mohs scale of hardness, which is a way scientists measure how hard minerals are.

While that’s pretty strong— strong enough to scratch glass, for example— it can’t beat diamonds. Topaz can be scratched by things that are harder than it.

Cleavage – Diamond has a cleavage in four directions.

A raw, soft pink diamond
Soft pink diamond photo provided by The Raw Stone

Cleavage is all about how a gemstone can split or break along certain lines based on its crystal structure. It’s like a built-in map that shows where the gem can be carefully broken to make shiny, smooth surfaces.

Topaz has a perfect cleavage in one direction. If you apply pressure in just the right way, it will split along a flat plane.

This ability makes topaz a bit tricky to work with when making jewelry because if it’s hit the wrong way, it might split. But, when handled correctly, this feature helps create beautiful gem cuts.

On the other hand, a diamond is a bit more complex when it comes to splitting. It has a different kind of cleavage, which is perfect but in four directions.

Because of this, cutting a diamond is an art that requires a lot of skill and knowledge. It’s why it can be shaped into so many different, dazzling forms that catch the light in amazing ways.

Streak – Topaz leaves a white streak.

Glassy and gemmy crystals of topaz on a matrix
Topaz on a matrix photo provided by Weinrich Minerals

A streak is the color of the powder a gem leaves behind when it’s scratched across a special plate.

Topaz and diamond have their unique way of showing off their streaks, or in diamond’s case, not showing it at all.

When you drag topaz across a streak plate, it leaves behind a white line. This happens because the powder is so fine that it doesn’t show the gem’s color, just the white of its crushed-up bits.

Diamond, though, is the show-off in the no-show department. It’s so hard that if you tried to make a streak with it, you wouldn’t get anything. The diamond just slides across the plate without leaving a mark.

This is because a diamond is the hardest material around, and the streak plate isn’t tough enough to scratch it and make powder.

Fluorescence – Some diamonds fluoresce under UV light.

A water-clear, colorless diamond on a matrix of gray-green kimberlite
Colorless diamond on kimberlite photo provided by @finemineralphotography

Fluorescence is a cool trick that some gems can do. It’s when a gem glows under ultraviolet light.

A diamond can be the life of the party when it comes to fluorescence. Some can glow bright colors like blue, yellow, or even green when they’re under ultraviolet light.

Not all diamonds do this, but when they do, it’s pretty awesome. This glow happens because of tiny bits of stuff inside it that react to the light.

Topaz, on the other hand, is a bit more chill about the whole fluorescence thing. Most of the time, it doesn’t glow under ultraviolet light.

But that doesn’t mean topaz isn’t special. It just doesn’t have the same kind of stuff inside that some diamonds do.

Conductivity – Topaz is an insulator.

Unique specimen of an etched bi-colored topaz
Bi-colored etched topaz photo provided by Saphira Minerals

Conductivity is about how well something can carry electricity. Think of electricity like a bunch of tiny runners, and the material they’re running through is the track.

Some tracks make it super easy for the runners to zoom through, while others are like running through peanut butter.

When it comes to topaz and diamond, they’re on different teams. Topaz is like a track made of peanut butter. It doesn’t let electric runners move through it easily at all.

It’s an insulator, a material that does not let electricity pass through it. So, if you tried to use topaz to conduct electricity, you wouldn’t get very far.

Diamonds, on the other hand, can be different. While most are also like running through peanut butter, some diamonds are like a super-fast track. These special ones can conduct electricity because of the boron inside them.

Location – Diamond is notably mined in Africa.

Several pieces of faceted fancy diamonds
Fancy diamonds photo provided by Rustic diamonds manufacturer

When you’re on the hunt for gems, knowing where to look is key. Each gem has its favorite spots on the map, too.

Let’s talk about the best places to find topaz first. It loves to hang out in places like Brazil, which is famous for its stunning and colorful topazes.

You can also find it in the mountains of Russia, the wilds of Pakistan, and even in the USA, especially in Texas, which named it the state gem. So, if you’re dreaming of finding topaz, these are some great places to start your adventure.

Now, if you’re wondering how to find diamonds, that’s a different kind of adventure. They’ve been found in different countries, but some of the most famous spots are in Africa, like Botswana and South Africa, where big mines have been discovered.

Diamonds are also found in Russia, Canada, and Australia. Finding them is a bit more tricky because they’re often found in and around old volcanic pipes.

Price – Topaz is more affordable.

A breathtaking specimen of a fine crystal of honey-orange topaz with glassy luster
Honey-orange topaz photo provided by Saphira Minerals

Comparing the prices of topaz and diamond is like comparing the cost of a nice bike to a fancy car. One is definitely more of an investment than the other.

Despite its amazing beauty, topaz is pretty affordable. You can get a really nice piece of topaz jewelry without breaking the bank.

The value of topaz depends on its color, clarity, and how big it is, but overall, it’s known for being a gem that gives you a lot of sparkle for your money.

The price of diamonds is a whole different story. Diamonds are famous for being one of the most expensive gems you can buy. This is because they’re super hard to find, really tough, and sparkle like crazy.

Its price depends on how big it is, how clear it is, its color, and how it’s cut. Diamonds can get pretty pricey, making them a big investment compared to topaz.

The Similarities

Although there are more differences between topaz and diamonds, these two natural wonders share an interesting similarity.

Magnetism – Both diamond and topaz are non-magnetic

A raw brown diamond with a perfect and complex growing pattern
Brown diamond photo provided by @finemineralphotography

Neither topaz nor diamond is attracted to magnets. This might not sound like a big deal at first, but it’s pretty useful for folks who love these gems.

Imagine you have a bunch of different stones and you’re trying to figure out which ones are topaz or diamond. If any of them were magnetic, they’d stick to a magnet.

But since both topaz and diamond are not, it’s one way to know you might have one of these special gems.

For people using topaz and diamond, this similarity in magnetism (or lack of it) is beneficial because it means these gems won’t mess with electronic devices.

Some gems and metals that are magnetic can interfere with electronics, but topaz and diamond are safe to wear around all your gadgets. This makes them perfect choices for everyday wear or fancy tech-filled events.

The Easiest Ways To Tell Them Apart

An Imperial topaz single crystal with intense colors
Imperial topaz photo provided by Mineral Masterpiece

When you’re out in the field, do you know how you can easily tell a topaz and a diamond apart? Here are some practical, doable tips you can try:

Do a scratch test

Diamonds are the hardest natural material on Earth, so they can scratch pretty much anything, including topaz.

If you have a gem and you’re not sure if it’s topaz or diamond, find an inconspicuous spot and try to scratch a piece of glass with it. If it leaves a scratch, you might have a diamond.

But remember, this test can damage the gem, so it’s best used on loose stones or with caution.

Fog it up

Just breathe on the stone like you’re cleaning your glasses and see how quickly the fog disappears.

Diamonds are great at conducting heat, which means they won’t stay fogged up for long if you breathe on them.

Topaz, on the other hand, isn’t as good at this, so if you breathe on your gem and the fog sticks around for a bit, it’s more likely to be topaz.

Check how it sparkles

Diamonds have a unique way of bending light, which gives them that incredible sparkle we all love. When you move it around in light, you’ll see bright flashes of white light mixed with colorful light.

Topaz sparkles too, but its sparkle is more about the colors and less about the bright white flashes.

So, if your gem dazzles with lots of white light, it might just be a diamond.

About Dr. Keith Jackson - Geology PhD

Keith Jackson is an avid rockhound who is constantly exploring new sites to expand his collection. He has worked as a professional Geologist for over 20 years and holds a PhD in Geology from the University of Nebraska-Lincoln, a Masters Degree in Geology from the University of Nebraska-Lincoln, and a Bachelors Degree in Geology from the University of Connecticut.

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