How Durable is a Diamond? (+Hardness and Wearability Info)

In this Learning Guide, we'll go over the factors of durability of a diamond, as well as gemstone durability in general. Plus, we'll answer these questions too: 

• Can diamonds break?
• What gemstones can be worn everyday?
• How are diamonds hard, but brittle?

Diamonds are Hard, But Brittle?

You may have heard that a diamond is the hardest natural material in the world. The world's understanding of hardness is different from the hardness we are talking about in diamonds and gemstones.

Because if a diamond was the hardest substance in the world, then why do we hear of the them chipping or breaking? Doesn't sound like the hardest material in the world would do that, does it?

That's because in the world of gemology, hardness doesn't equal durability. It is only one of the many factors that contribute to a gemstone's wearability or overall durability for everyday wear.

Gemstone Hardness

All minerals have a measurable hardness rating. Jewelry settings, gemstones, glass, lab created minerals have a hardness rating on the Mohs Hardness scale. The Mohs scale is a rating system of 1-10 that determines the scratch resistance of minerals.

A diamond reaches a 10 on the Mohs scale. Diamond is the hardest natural substance found within the earth. No other mineral or gemstone resists scratches like a diamond. Only a diamond can scratch a diamond.

A lot of people think the only reason diamonds are marketed as the choice gemstone for engagement rings and wedding bands is because of how much more expensive they can be than most colored gems. In actuality, it has a lot to do with the scratch resistance to dust over years and years of wear.

But remember, gemstone hardness is about being able to be scratched. It doesn't have anything to do with chipping or breakage. That's another factor to consider when choosing a durable gemstone.

Dust and dirt particles creating fine scratches on your stones are the biggest threats to them. But not with diamonds.

Gemstone Cleavage Planes

Cleavage planes have more to do with chipping and breaking. It has nothing to do with scratchability. This physical attribute of a gemstone can be hard to understand because it has to do with natural crystal structure of a stone.

Sometimes you'll hear the words "cleave" or "cleavage" in the gemology world. This is referring to a gemstone's ability to split or break along what's called a cleavage plane. Only crystalline minerals have cleavage. The cleavage plane is a weakness in the atomic bonds of the stone's crystal structure. It's about how strongly the molecules in a gemstone bind together.

Gems can cleave in multiple directions too. Diamonds have the ability to cleave in four directions. This means the structural integrity of a diamond isn't the best when it comes to hard blows.

Most transparent faceted gemstones have cleavage planes. Just as wood can split, so can a stone. The different faces of the crystal structure are planes. This means that if struck hard enough, the stone will break along the cleavage plane.

Read also: What is the Refractive Index of a Gemstone?

Each gemstone has a cleavage rating. They can be rated as the following:

• None
• Poor (or weak)
• Fair (or moderate)
• Good (or imperfect)
• Perfect

Gemstones with perfect cleavage are more likely to split along a plane. The carbon atoms in the crystal structure, much like wood grain. They can split, shatter, or chip. However, this doesn't mean that it will happen for sure if you accidentally hit or drop your diamond ring. It just means that risk is much higher with certain stones. Diamonds are known to have perfect cleavage, meaning it is more likely they will break along a cleavage plane.

Gemstone Fracturing

Like gemstone cleavage, fracturing has to do with gem or diamond breakage. Any breakage in a stone unrelated to a cleavage plane is considered a fracture. Diamonds are considered to have a conchoidal fracturing type. The type of fracture ratings are as follows:

• Conchoidal — breaks in concentric curvy lines
• Fibrous (Splintery) — breaks and creates spindly, sharp points in a stone
• Hackly — Creates rough, jagged points in a stone when broken
• Uneven — Creates rough texture without sharp points

Gemstone Wearability for an Engagement Ring

The overall wearability of a stone takes into account gemstone hardness, gem cleavage, fracturing, and parting when determining a wearability grade for stones. The wearability grades are as follows:

• Excellent

• Very Good

• Good

• Poor

• Collector's Only

Keep in mind that the overall gemstone wearability grade of a stone isn't actually set in stone. The way you take care of your stones will also have a lot to do with their longevity. How often you wear it, how you store your jewelry, how often you clean it, etc. It all impacts the overall durability.

What Can Make Diamonds Stronger?

If you've been shopping around for diamonds lately, you've probably found out that not all diamonds are the same. They'll tell you less about them in stores as their attention is more fueled toward meeting a sales goal, not for education.

We know that diamonds have the best scratch resistance, but are susceptible to chipping and splitting if accidentally struck. But is there anything you can do to decrease the chances of this happening?

There is.

Obviously there's no magic spell to wave your wand over your diamond (Improvius Durabilitis!) and increase its overall durability. But there are simple things you can consider when choosing your diamond engagement ring.

How Diamond Cutters Can Affect Diamond Durability

One of those is choosing cut quality for your diamond. For round cut diamonds, that means choosing a cut grade. You should choose an ideal cut diamond for superior light performance and stability in your diamond.

You see, the cut quality of your diamond can affect the durability of the jewelry piece. If you choose a poorly cut diamond, the crystal structure is compromised. When the cut quality is bad, the durability is as well. Add bad gem cutting on top of diamond's cleavage and fracturing-it's not a good combination.

Round diamonds are the only diamond with an official cut grade on a diamond grading report. There are specific ranges for measurements and proportions for other diamond shapes. By choosing a diamond that falls within the "ideal proportion range" of that shape, you can ensure that your diamond's stronger.

Read also: Best Place to Buy Round DIamonds Online

The cut quality of your diamond is what determines its shape and proportions. If a gem cutter doesn't cut a diamond properly, the proportions are uneven and unbalance, compromising the foundation of the diamond.

Choosing a Protective Ring Setting

The other thing you can do to protect your diamond from breakage or cleaving is to choose a protective ring setting. Prong settings are good for covering the edges of your diamond. The girdle of a diamond is what breaks or chips the most when it happens.

Low profile ring settings are also a good option. Tall prong settings can snag on fabrics and be more likely to bump throughout the day. Consider lower settings like a bezel setting or a flush setting. 

Read also: Is a Flush Setting Right For You?

Diamond Durability FAQ

Do All Diamonds Have the Same Durability?

There are different diamond types than just natural diamonds. Lab created diamonds have the same physical properties as natural diamonds. That means they don't easily scratch, but still cleave and fracture. The same is true for both natural fancy colored diamonds and lab created fancy colored diamonds.

Read also: Best Place to Buy Lab Created Pink Diamonds Online

What Gemstones Have a Best Wearability?

All of these stones are considered good if worn everyday. However, the longevity of each stone may outweigh another stone's wearability, depending on where they fall in among other contributing factors of durability.

• Moissanite (a lab created diamond simulant)

• Corundum Gemstones (Sapphire and Ruby)

• Cubic Zirconia (lab created diamond alternative)

• Alexandrite

• Topaz

• Aquamarine (Beryl)

• Morganite (Beryl)

• Emerald (Beryl)

• Spinel

• Garnet

• Quartz (Clear quartz, rose quartz, smoky quartz)

• Citrine (Quartz)

• Amethyst (Quartz)

Are Diamonds the Most Durable Gemstone?

Diamonds aren't considered the most durable. Their gem hardness may be on par, but the susceptibility to chipping and breakage compromises that durability. With perfect cleavage in 4 different directions and the ability to fracture, diamonds are breakable. Easily split if hit hard enough.

Some people like the option of choosing a colored gemstone. But not every ring stone can withstand the years of a marriage.

So what are the best colored gemstones for daily wear? 

The answer to that is corundum. Corundum is both sapphire and ruby. Sapphires occur in a variety of different shades, not just blue sapphire like most people think. Sapphire is every color, except red. Red corundum is better known as ruby, the July birthstone.

Read also: Ruby Jewelry vs Garnet Jewelry 

Neither sapphire nor ruby have cleavage planes. Unlike a diamond, a sapphire or ruby can't be easily split. They don't have any gemstone cleavage, but can fracture. The likelihood of chipping a sapphire if hit is still pretty low. Not impossible, but unlikely.

Additionally, corundum reaches a 9 on the Mohs scale. Even though 9 is right next to 10 (where diamond sits at), it doesn't mean the hardness is close to the same.

The distance between 9 and 10 in the gemology world is different than one number away, as it is with the rest of life. In actuality, diamonds are 4x harder than sapphire or ruby. Sapphires and rubies are 2x harder than topaz, which sits at an 8 on the scale.

So while diamonds and topaz may only be two numbers away from each other, the actual scratch resistance between the two is much different.