Can Gemstones Crack and Why?

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Dealing with gemstones all the time, I had several unfortunate experiences of cracking and breaking them.

Maybe you had experienced this too.

In this article, I’m going to show you the reasons why gemstones crack, how to avoid it, and what to do after it happens.

Instead of looking at the astronomical and metaphysical reasons, I’ll solely focus of the physical ones and the gemology of gemstones.

Why Do Gemstones Crack?

Drop or Physical Contact

One of the most common reasons of gemstone cracking is due to physical contact. Simply dropping or banging your gem can crack and break it.

Some gemstone cuts are more prone to cracks. Pointed edges like in a marquise cut gem would be more easily damaged compared to beads in a bracelet.

Natural Fractures from Gemstone Formation

Continuing from the last point, gemstones also have fractures and inclusions that are inducive to cracks. Some can be small and some can be big. The small fractures may not even be visible to the eyes. However, during impact, the gemstone would crack and break along those fractures. Also, they can develop over time to reach the surface due to wear and tear.

Some gems naturally have more fractures, which can easily lead to cracks. To describe the clarity of gemstones, gemstone industry has separated different gems into different categories, from type I gemstones usually having the least amount of inclusion/fractures (clean gemstones) to type III gemstones that are usually included. Here are some examples of each type:

Type I

  • Beryl (Aquamarine and morganite)
  • Some quartz (e.g. light color amethyst and smoky quartz)

 

Type II

  • Corundum (ruby and sapphire) 
  • Garnet
  • Peridot
  • Some quartz (e.g. deep color amethyst and citrine)

 

Type III

  • Emerald
  • Some tourmaline (e.g. red tourmaline and watermelon tourmaline)

Extreme Change in Temperature and Humidity

Some gems like opal and ammolite can crack under dehydration. Opal has a high water content (up to 10%). Extreme heat with low humidity could cause an opal to dry out and crack. Ammolite could also crack under extreme sunlight.

Moonstone, labradorite and other feldspar gemstone can crack if the temperature change is sudden and extreme.

birthstone-october-triplet-opal
Opal can dry out and crack under extreme heat and low humidity

How to Avoid Gemstones From Cracking?

Avoid Dropping

This one’s obvious. Dropping and banging into hard objects are the main reasons why gemstone crack. Avoid them to protect your gem.

Stable Storing Conditions

Seraphinite bracelet by Unearthed Gemstones. Photo by noiarkobi.

Your gemstone should be stored in a stable temperature and humidity. Also avoid contact of different gems to avoid damage by impact.

Don’t Buy Certain Treated Gemstones

Dyed crackled quartz beads

Some quartz is treated by very high heat, and subsequently dunked into cold water. This causes the quartz to crack. It’s sometimes known as “crackled quartz” in the market. This quartz as you can imagine is prone to cracks and damage.

Ruby and sapphire sometimes are treatment with very high heat. The heat is so high that some natural inclusions inside the gem (could be other minerals) expand rapidly, more so than the host stone (the ruby or sapphire), causing the host stone to crack because of the high pressure.

Changing to Protective Setting Before Cracking

If you notice a fracture that reaches the surface, there are things to do to avoid it from cracking. Change to a more protective setting, like bezel or inlay setting, could help it from further damage and maybe can save it from breaking.

What to do if the Gem Cracks and Breaks?

Replacing the Gem

Usually for a broken gemstone, the most economically way would be to replace it, as you can see the other options are more costly and time consuming most of the time. However, if the gem means something special or if the damage is not serious, you can consider the following suggestions as well.

Changing the Setting

Depend on the location of the crack and the size of the crack. Sometimes it can be set in a different setting to hide the damage. For example, a bezel setting can hide some small chips on the side or make them less noticeable.

Recutting the Gem

Sometimes if the crack/chip is small and on the side, the gem can also be recut into a slightly smaller gem

If a big sized gem is unfortunately cracked and broken into two or more sizeable chunks, it’s possible to find an expert to recut and polish into smaller stones. However, this could be costly and the gems after cutting could be much smaller than the original one.

But any type of recutting could be a complicated process, especially for faceted stones. A professional lapidarist can evaluate and advise what’s best to do in your situation.

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