The other day, I dropped one of my gemstones, and it broke on impact. It makes me think, why gemstone breaks when it’s dropped.
After doing the research, here are the reasons why gemstone break and ways to avoid that from happening to your gem.
Why Gemstone Breaks When Dropped
The main reason a gemstone can break is because of impact. It can be from a drop, a hit to a wall, or some other forms of impact.
Gemstone is made up of different atoms, and they are held together by bonds to form the gemstone you know and love. Upon impact, the bonds that holds the atoms together can break, and that means the gemstone breaks.
Gemstone Hardness vs Durability
A lot of people think harder gemstone will be more durable. In that sense, the hardest gemstone, diamond will be the most durable.
But it’s unfortunately not.
Harder of gemstone only means that it can withstand scratches more easily. And it doesn’t have anything to do with whether the stone will shatter if you drop it. Hardness is only one of the factors to determine whether a gemstone is durable.
What Is Gemstone Cleavage?
As International Gem Society puts it, “Just as wood is easier to split with the grain than against it, gemstone cleavage is the tendency of certain crystals to break along definite plane surfaces.”
One of the big factors that makes the gemstone breakable is the cleavage (Don’t worry, I’ll keep the technical jargon to a minimum.)
Gemstones are made with atoms. There are bonds holding the atoms together. And how strongly those bonds are is the cleavage of that gemstone.
Gemstone cleavage is described in several grades:
You may think perfect cleavage would be better, right? But it’s the other way round.
Gems with perfect cleavage is the easiest to split and fracture. Gemstones like diamond, topaz and moonstone have perfect cleavage.
Stones with no cleavage, like nephrite, is very strong and can withstand much more of a hit than those with perfect cleavage.
Some gemstones have different cleavage on different ‘sides’, or technically, planes of the gemstone. For jewelers, it’s important to consider the side most exposed should be the stronger side.
What Is Fracture Toughness Scale?
A scientific way to measure the toughness of material is called the Fracture Toughness Scale. This scale measures how easy it is to split and break a gemstone.
For example, the most durable gemstone is nephrite which scores 225,000 on the scale. And a weaker gemstone like ruby has a number of 600.
Which Gemstones Are The Most Durable?
Nephrite and jadeite are the most durable gemstones. With fracture toughness scores of 225000 and 120000 for nephrite and jadeite respectively, they are very tough and can withstand most of the abuse from daily wearing.
The reason that they are so tough is their dense and interwoven fibers, more so for nephrite.
Is Higher Quality Gemstone Less Breakable?
Gemstone quality can affect durability. Usually the higher the quality, less flaws it will have, and so it could be less likely to break.
For example, comparing a quartz with no flaws and another one with some natural fractures, the one with fractures would be more prone to breakage. This is especially true if the fracture reaches the surface of the gemstone.
Can Gemstone Treatment Affect Breakability?
Gemstone treatment sometimes affect gemstone more than its appearance.
Heat treatment is one of the most common gemstone treatments. Some gems like ruby and sapphire are heated to a very high temperature. It can weaken the internal structure of the gem and make it easier to break. Or sometimes there are other minerals inside the gem which expand more than the host gem. This may make the gem crack from within.
Fracture filling is another gemstone treatment that may affect the breakability of gemstone. Emerald and ruby are two gems that get this treatment frequently. Sometimes the material used for filling the fractures is softer or don’t adhere to the gemstone well. And this can make it break more easily.
Which Gemstone Cuts Are Prone To Breaking?
Some cuts with pointed edges and corners will make the gem have weak spots prone to breaking.
For example, a marquise cut which has two pointed tips, is elegant but creates two places that the gem is weak to hits.
If you plan to wear the gem as a ring and don’t want the stone to chip too easily, cuts without sharp edges, like an oval cut, will be more durable and can withstand more abuse.
How To Avoid Gemstones Breaking?
For gemstones that are easy to break, a protective setting may be used. Just like your phone case, it protects the gemstone from abuse of everyday wearing. And it will keep the gem in good condition for longer.
Here are some examples of protective gemstone settings:
For this setting, the gemstone is cut to fit in an opening in the metal setting. The metal can protect the gemstone. It’s a popular setting for turquoise, which is a softer gemstone.
The metal is wrapped around the gemstone and protects the edges. However, the top of the gemstone, which may stand taller than the metal, is exposed and can still be damaged.
Also, gems set in a ring will be more prone to damage than those set in pendants or earrings.