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Is There A Gem Harder Than Diamond?

Is There A Gem Harder Than Diamond?

Diamonds have a particular reputation that follows them wherever they go. For one, they hold value incredibly well; it’s a known fact that they are a foolproof investment. But there is one more part of their reputation that we want to focus on today – hardness.

You’ve probably heard about diamonds being the hardest material on the planet. They’re incredibly resilient to heat and pressure and are impossible to scratch with anything other than – well, other diamonds! 

But if these stones are so tough, does that mean that there are other gems that are just as, or even stronger, than diamonds? Is there a gem harder than a diamond? 

Well, the straight answer is no – but we need to elaborate on a few things because it’s not that simple. 

First of all, what the heck does it mean for a material to be hard? How does the scale work? We did some research and found the answers. So, let’s get this thing going and see if we can explain a few of our findings. 

Is There A Gem Harder Than Diamond?

As we already mentioned, there are no materials in the world that are harder than a diamond. On the Mohs scale, it occupies first place with a score of 10. The number two spot goes to the mineral corundum with a score of nine on the scale. 

But the difference between diamond and corundum is much more significant than it might seem.

But let’s take a deep dive into this Mohs scale. You might be wondering what it means for a material to have a good score on the “hardness” scale. Well, it may not be what you think. 

It would seem logical for the scale to represent something along the lines of how hard it would be to break it apart.

But here’s the thing: The hardness scale only shows how resilient the material is to scratching. 

We know it seems strange, but that’s all that the Mohs scale is referring to. And considering that a diamond can only get scratched with the help of another diamond, it makes sense that it would be the undefeated champion in the category. 

But there’s more to diamonds than just how hard they are. 

Sure, the incredibly hardness helps them for industrial use, but they’re actually much more sensitive than you think. See, there are many other factors to how strong a gem is; it being tough to scratch is merely the tip of the iceberg. 

The scratching is essential for a simple reason – jewelry tends to get scratched up a lot in its lifetime. 

For instance, an opal might be good-looking when it’s freshly cut and sold, but over time, the scratches will make it lose its shine and sparkle. And that means that the value will go down over time, too. 

When we take this into consideration, it becomes apparent why diamonds are considered to last forever. 

But let’s look at what the other strength-related factors are. 

Gems are graded for hardness, tenacity, wearability, cleavage, and jewelry settings. When we take all of these things into consideration, the Mohs scale starts to seem less important. 

But we can assure you that there’s a good reason for it to exist. Let us explain.

What Is The Mohs Scale? 

The Mohs scale was created back in 1822 by German geologist Friedrich Mohs. The scientific community looks down upon the scale for the lack of accuracy in anything other than geology. 

Not that it matters: Geology is what it was created for – and it’s doing a fine job in the field to this day. 

Geologists use the scale to check their findings on the spot by simply scratching the material they found. It’s pretty simple: If you think you found a diamond, but you manage to scratch it with anything other than a diamond pick – it’s not a diamond. 

These days, though, the scale got a bit of a revival since it’s being used to test smartphone screen glass’s hardness. 

So, with all that said, as far as hardness goes, nothing beats a diamond. 

The not-so-close second is corundum, such as sapphire and rubies. They can’t be stretched as easily as quartz, for example, but are soft compared to diamonds. 

Learn More:

Is Diamond The Strongest Material In The World?

So, there’s no question about it: Diamonds are the hardest material on Earth, meaning that there’s a slim chance of them getting scratched up during their lifetime. They will shine and sparkle forever! 

But are they the strongest material in the world? Well, no – far from it, really.

Diamonds are no joke; let’s get that straight. They don’t mess around. But if we look at some other properties and factors, the story looks quite a bit different. 

Heck, if you don’t know what you’re doing, a diamond will shatter into a bunch of little pieces while getting cut. They are pretty brittle compared to other materials that would be in the talks for the strongest one in the world. 

Let’s explain what those factors are so you get a better understanding of what we’re talking about here.

See Also: Will A Diamond Shatter If Heated?


The tenacity of a mineral is a measurement of how resistant a gem is to blows. Diamonds, for instance, have a very low tenacity. So, even though it’s incredibly resistant to scratching, it will shatter to pieces if hit under a certain angle with a moderate force. It seems strange, we know! 


A wearable grade tells us how much wear and tear a gem can endure over time. Well, tearing might not be an issue for gemstones – but you get the point. 

The word “durability” is often used in these descriptions, as well. It tells us how many scratches will be visible on the surface of the gem during its lifetime. 

That’s another instance in which the Mohs scale steps in and makes itself useful. Diamonds will obviously show no scratches as they can’t get scratched by anything other than other diamonds – but rubies are not that far behind. 

Sure, there’s a big difference in the score on the scale between these two, but still, rubies can’t just get scratched up with any material. Gems begin to lose their shine with enough scratches as light can’t go through the surface as easily as when they’re brand new and freshly cut. The grades go like this – excellent, very good/good, poor, and display only.


Cleavage planes are essentially the building blocks of gems. It is, in a sense, a way to grade the bond between the atoms of a gemstone. 

Diamonds are only made of carbon, and their atoms are packed together incredibly tightly. That’s one of the things that makes them the hardest material in the world.

But because of the way gems are generally formed – one plane on top of the other – they are usually very prone to coming apart. There are, however, certain gems that don’t have cleavage planes. 

The grades that are used for this category are the following – perfect, good, fair, and poor. 

Read Also: Is Steel Harder Than A Diamond?

Are Rubies Stronger Than Diamonds?

We’ve already mentioned rubies a couple of times. It’s no surprise, really; they are in second place on the already mentioned Mohs scale. 

So, if that scale is only essential for scratches that a gem can develop on its surface, could ruby be stronger than diamonds when we consider all of the other factors we talked about previously?

Well, it’s a bit more complicated than just a “Yes” or “No” answer that you might’ve been expecting. 

First of all, rubies are not on the Mohs scale; corundum is. The material can become a crystal and turn into a ruby under particular conditions. 

But are these red gems strong enough to hold their own against diamonds? Well, as we already mentioned, it all depends on gem cleavage – at least if we’re talking about “strength.” 

Unfortunately, diamonds and rubies are formed in very similar ways even though they’re not made of the same material. That means that they have similar plate cleavage. 

Corundum is an incredibly hard material that is often used to cut other gems – but just like diamonds, it’s brittle. 

Interestingly enough, gems that rank lower on the Mohs scale have much less plate cleavage, which means they can withstand much more force before breaking apart. Does this matter, though? Diamonds and rubies are mainly used and sold as jewels, so why would this factor be important?

Well, sure, we admit that all this doesn’t matter in the context of perfectly cut diamonds and rubies – but the question was if there’s a gem out there harder than diamond, darn it! We feel that it is essential to know what all these phrases mean. 

People often hear that diamonds are the “hardest” material on the planet. And they are – but it all sounds a bit less sensational if we know that they just can’t get scratched easily. 

Are Diamonds Useful For Anything Other Than Jewelry?

How about we take a look at what diamonds can be used for aside from jewelry. The world’s hardest material probably has some use for industrial purposes, right? 

Well, yes! Diamonds have been used in many industries for a long time. 

As a matter of fact, most of the diamonds that are mined are thrown for industrial use when they’re not deemed as gem-grade stones. Only about 27 metric tons of diamonds are gem-graded and shipped out to be cut and prepared for sale. 

That does seem like a lot – and it is, don’t get us wrong. But diamonds are not a rare occurrence, so that number is actually relatively low. 

Which diamonds get the high grades and which don’t might seem like it’s not the most accurate and planned out process. That’s because it very much depends on what the industry needs at that particular point in time. 

See, the diamonds industry pretty much controls the supply and demands all on its own.

There are just a handful of companies that mine for and sell diamonds to everybody else. So, if they deem that there are just too many diamonds on the market for their taste, they start shipping more of them for industrial purposes. 

These primarily include drilling and cutting, as the crystal rocks shine brightest in these fields, so to speak. 

But there are other jobs they can fill; they’re even great for high pressure or heat experiments in many science fields. That’s because they can withstand extreme heat and pressure, more than many other materials that just happen to be harder to find than diamonds.

So, why diamonds? What about rubies, for instance? Do they not have the same industrial potential? Well, they do to a degree – but there’s a big problem with using them for these purposes. 

They are much rarer than diamonds. Even though they are plenty hard, tough, and pressure-proof, it’s just much harder to find a ruby in nature, so it would be a shame not to use them for beautiful jewelry.

Final Words

So, there you have it. The answer to “Is there a gem harder than diamond?” can be summed up as follows: 

Diamonds are the hardest gem out there. Even if we start including other factors into the mix, the translucent gems seem to come out as winners. 

But who knew that they’re so brittle, despite their tough reputation? It just goes to show you that it’s not all about how dense the material is; the most important thing is how it’s put together!

And sure, there are some opals and crystals that would hold up better if they get hit with a hammer; we’ll give them that. 

But at the end of the day, we’re always choosing diamonds as our favorite gems. It’s not even a competition!

See Also: Is Opal Worth More Than Diamond?