Can You Break a Diamond ?

Everyone knows diamonds are the hardest natural substance on Earth. It’s right there in every gemstone 101 guide. But here’s something the jewelry store won’t always tell you: hardest doesn’t mean indestructible.

While diamonds rank a perfect 10 on the Mohs scale for hardness (meaning they resist scratching better than anything else), they can still break or chip, especially if they’re handled carelessly or hit the wrong way. And surprisingly, a lot of that damage happens before the diamond even reaches a jeweler’s workbench.

What Happens at the Process Plant Doesn’t Stay at the Process Plant

When rough diamonds are mined, they go through some pretty aggressive handling in what’s known as the process plant—the place where they're separated, cleaned, and sorted. This isn’t exactly gentle spa treatment for stones. We’re talking about:

• Crushing

• Screening

• Mechanical sorting

• High-pressure flow systems

If any of that equipment is oversized, misconfigured, or poorly maintained, it creates the perfect environment for a diamond to fracture, especially if it has inclusions (internal flaws) or cleavage planes (natural zones of weakness in the crystal structure). It's kind of ironic—nature creates the hardest substance on Earth, and then we put it through a blender.

The Weak Spots Inside

Not all diamonds are created equal on the inside. Many rough stones have:

• Inclusions (tiny cracks, minerals, or air pockets trapped during formation)

• Cleavage planes (directions along which the diamond naturally splits)

Even a light impact in just the wrong direction can cause a crack to propagate. That’s why some seemingly durable stones can break during processing—it’s not always the pressure, but the presence of these internal vulnerabilities that matter.

Shape Matters (More Than You Think)

Once a diamond is cut, the risk doesn’t completely disappear. Certain shapes—like marquise, pear, and princess cuts—have sharp corners or pointed tips, which makes them more susceptible to chipping, especially during setting or everyday wear.

Think of it like glass: a round drinking glass is harder to break than one with sharp edges.

Mishandling After the Mine

The journey from mine to market is long, and not every step is kind to these stones. Improper packaging, rough shipping conditions, or even careless handling at a cutting facility or auction house can turn a high-value diamond into one that’s heavily discounted due to damage.

And in the luxury gem world, even a tiny chip can mean thousands of dollars off the price.