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What is the Mohs Scale? Atencio's Guide to Gemstone Hardness

gemstone hardness, mineral hardness, mohs scale
7/7/2021
What is the Mohs Scale? Atencio's Guide to Gemstone Hardness

When it comes to choosing the right gemstone for your jewelry, you have to strike a balance between beauty and “wearability.” This last trait hinges on a gem’s ability to hold up against everyday wear and tear. If the stone lacks durability, it may easily scratch. Fortunately, you can use the Mohs Scale to determine which gems are appropriate for everyday wear.

What Makes a Gem Hard?

Gemstone hardness is a widely misunderstood concept. In regard to jewelry-grade gemstones, hardness is the ability to resist scratching.

If you polled an ordinary group of people, they would agree that cotton is soft and glass is hard. In terms of gemology, however, glass is regarded as a soft material. This is because there are a variety of materials that can easily scratch it.

In scientific terms, hardness depends on the bonds that keep atoms together inside a crystal structure. When something scratches, it’s because a harder material was able to break millions of these bonds. With that said, to understand gem durability all you need to know is that hardness really refers to “scratchability.”

Every gemstone can be rated based on whether other minerals can scratch it, and this is where the Mohs Hardness Scale comes in.

How it Works

The Mohs Hardness Test is one of the most widely used tests for identifying and classifying gems.

The test rates a gemstone’s hardness on a scale of 1 to 10. To get a numerical value for hardness, the test includes a baseline of 10 minerals that have ascending values for hardness. The minerals contained in the scale include ( from softest to hardest):

  • Talc
  • Gypsum
  • Calcite
  • Fluorite
  • Apatite
  • Orthoclase
  • Quartz
  • Topaz
  • Corundum
  • Diamond

If a gemstone can be scratched by any one of these minerals, it receives the corresponding maximum hardness value. For example, since emeralds can’t be scratched by quartz but can be scratched by corundum, they have a ranking of 7.5 – 8 on the Mohs scale.

Choosing the Right Gemstone

Many people assume that all gemstones should be durable; after all, they are stones, aren’t they? In reality, not all precious gems have the same durability as diamonds.

diamond ring with a mohs hardness of 10

While other gems can be beautiful and dazzling, they often lack the same strength and scratch resistance. This isn’t necessarily a major problem if you know how to protect them. That said, certain gems will not hold up well for people who work with their hands, engage in rigorous fitness routines or live very active lifestyles.

When choosing a gem for your jewelry, it’s important to consider how it will hold up to everyday wear. But what does everyday wear really mean? The answer is different for everyone. To make a wise purchasing decision, you have to take a personalized approach that factors in an individual’s job and lifestyle. This is especially true if you’re buying an engagement ring. For instance, since diamonds have a 10 Mohs rating, they are ideal for everyday wear, even for women who live active lifestyles or work with their hands.

With a rating of 10 on the Mohs scale, diamonds are the hardest jewelry gemstones known to man. This is just one of the many reasons they are the preferred choice for engagement rings and other jewelry intended for everyday wear. Moissanite, a naturally occurring gem that can also be grown in a lab, is nearly as hard as diamond, with a Mohs rating of 9.25. With a ranking of 9 on the Mohs scale, rubies and sapphires are also beautiful and durable options for rings and other jewelry intended for daily wear.

That said, anything below a 7 is generally considered to be a riskier choice for a ring. This would include pearls, which have a Mohs rating of 2.5 – 4.5 and opals, which have a Mohs rating of 5.5 – 6.5. It doesn’t mean you can’t incorporate these stones into your designs. It just means you will have to use exceptional care to keep them from scratching.

While a clear understanding of the Mohs Scale can help you select the right gems for your jewelry; it’s also especially helpful to have insight from a knowledgeable jeweler who can help you select a beautiful stone that’s appropriate for your jewelry and lifestyle.

Coupled with John Atencio’s masterfully crafted jewelry pieces, the right gems create a stunning artistic expression of luxury. Explore our jewelry collection online or schedule an appointment at one of our convenient locations, where our attentive team will provide a personalized approach to help you find beautiful and durable gemstones for your jewelry.