On SLC Ring Stone Hardness and the Mohs Scale

ring stone hardness Mohs

There are several important qualities you’ll be considering for any gemstone you’re looking at for a ring, whether you’re thinking about a diamond or any other type. One of the single most vital among these qualities, and which many buyers are paying close attention to, is the hardness of the stone.

At AAA Jewelers, we’re proud to offer a wide range of custom bridal jewelry, fashion jewelry and more to clients in Salt Lake City and surrounding parts of Utah, and gemstone rings are our specialty. What exactly do we mean when we talk about gemstone hardness, which other factors play a role in stone durability overall, and what is the Mohs scale for measuring stone hardness? Let’s take a look.

What is Gemstone Hardness?

When it comes to hardness, we’re really talking about a gemstone’s resistance to scratching and other surface damage. This quality is determined by the stone’s chemical make-up and how tightly its molecules are bound together. The harder a stone is, the more difficult it will be to scratch or chip the surface.

For instance, a very hard stone like a diamond (which rates a 10 on the Mohs hardness scale – more on that shortly) will resist scratches and surface damage much better than a softer stone like opal (which rates only a 5.5). However, it’s important to keep in mind that hardness is just one factor affecting a gemstone’s overall durability. Jump to our next section for more on that.

Other Factors in Gemstone Durability

As we alluded to above, while hardness is very important for many buyers, it’s actually just one of a few factors that affect a gemstone’s durability. In addition to hardness, you’ll also want to consider a stone’s toughness (resistance to chipping and breaking), cleavage (the way the stone breaks when hit with force), and stability (resistance to heat, chemicals, light, etc.).

For most buyers, the ideal stone will have a good mix of all these qualities. However, some stones (like opals) may be soft but have very high toughness, making them more resistant to surface damage overall. Ultimately, it’s up to you to decide which combination of qualities is most important for your needs.

What is the Mohs Scale?

Named after German mineralogist Friedrich Mohs, the Mohs scale is the most commonly used method for measuring gemstone hardness. It rates stones on a scale from 1 (very soft) to 10 (very hard), with diamonds being at the top of the scale. Here’s a quick overview of where some popular gemstone types fall on the Mohs hardness scale:

  • Diamond (10) – As we mentioned, diamonds are the hardest known natural material on Earth. They’re virtually impossible to scratch and will resist surface damage better than any other type of gemstone.
  • Moissanite (9.25-9.5) – Moissanite is a man-made stone that’s very similar to diamond in appearance but slightly less hard. It’s still an excellent choice for rings and other jewelry, however, as it will resist scratching and surface damage very well.
  • Sapphire (9) – Sapphires are a type of corundum, which is one of the hardest materials on Earth after diamond. They’re very scratch-resistant and make an excellent choice for rings and other jewelry.
  • Ruby (9) – Like sapphires, rubies are a type of corundum and are very scratch-resistant. They’re a great choice for rings and other fine jewelry.
  • Emerald (7.5-8) – Emeralds are a type of beryl, which is a relatively soft stone. However, they’re still quite durable and make a beautiful choice for rings and other jewelry.
  • Opal (5.5-6.5) – Opals are a type of hydrated silica, which is a very soft material. As a result, opals are more susceptible to scratching and surface damage than harder stones. However, they’re still quite tough overall and make a beautiful choice for rings and other jewelry.

As you can see, there’s a wide range of hardness levels among different gemstone types. Ultimately, it’s up to you to decide which type of stone is right for your needs.

“Soft” and “Hard” Ranges

Some gemstone buyers will hear discussion of these stones as either “hard” or “soft” in nature, and may wonder which parts of the Mohs scale are being referred to with each term. And while the answer here may vary slightly from person to person, the general consensus is that the crux point here is somewhere around 7 on the Mohs scale.

That is, most gemstone buyers and enthusiasts will consider any stone with a hardness rating of 7 or above to be “hard,” while those with a hardness rating below 7 will generally be considered “soft.” Of course, as we mentioned earlier, hardness is just one factor affecting a gemstone’s overall durability. So even “soft” stones like opal can still be quite tough and resistant to surface damage.

The takeaway here is that you shouldn’t necessarily rule out a stone just because it falls on the “soft” side of things. Instead, look at the stone’s overall durability (including factors like toughness, cleavage, and stability) to get a better sense of how well it will hold up over time.

“Hard” gemstones like diamonds, moissanite, sapphire, and ruby are excellent choices for rings and other jewelry, as they will resist scratching and surface damage very well. “Soft” gemstones like emeralds and opals are also beautiful choices for rings and other jewelry, but may be more susceptible to surface damage — and you just need to consider this.

Maintenance Differences

Finally, there might be some slight differences in maintenance required for “hard” and “soft” gemstones. In general, you’ll want to take a slightly gentler approach when cleaning and storing “soft” gemstones like emeralds and opals, as they may be more susceptible to scratching and surface damage. For example, you might want to use a soft cloth instead of a brush when cleaning these stones, and be careful to avoid contact with harder materials that could scratch them.

“Hard” gemstones like diamonds, moissanite, sapphire, and ruby require less special care, as they’re more resistant to scratching and surface damage. However, you’ll still want to take care when cleaning and storing these stones, as they can be damaged if not treated properly.

For more on this, or to learn about any of our diamond or other gemstone ring options for SLC clients, speak to our team at AAA Jewelers today.