What is Mohs Hardness Scale and Why is it Significant in Jewelry
Oct 15, 2024
“Gems, in fact, are a species of mineral flowers; they are the blossoms of the dark, hard mine; and what they want in perfume, they make up in durability,” said writer Harriet Beecher Stowe. Indeed, durability is one of the key hallmarks of a good gemstone. They are precious and desirable primarily because they withstand the tests of time and wear and tear. That said, not all gemstones are created equal. Some are softer and more malleable, while others are hard enough to slice through the glass! How, then, does one measure this element of durability? One way to do so is to measure the gemstone’s hardness. The harder it is, the more durable and damage-resistant it is. There is a credible method to assess its hardness attribute, a technique that has been used for over two centuries and honed over time – the Mohs Hardness Scale.
Introduced by a German mineralogist, Friedrich Mohs, in 1812, it started off as a way to classify minerals by their physical characteristics. How did he measure strength and hardness? The scale is essentially based on differentiating which gemstone can scratch the other. So, a harder gemstone that scores higher on the Mohs scale can scratch a softer gemstone that scores lower. The Mohs scale was initially meant to take into account all minerals. However, over time jewelers realized that it is better applied specifically to gemstones to study their properties and use the information in making and maintaining jewelry. For this, it is first important to understand the Mohs hardness scale.
The hardest mineral on the scale is the diamond, scoring 10. Any other mineral on the Mohs hardness scale cannot easily scratch a diamond. On the other hand, Corundum, which is the umbrella mineral for both sapphires and rubies, scores a 9 on the Mohs scale. Both sapphires and rubies, and any other gemstone scoring a 9 on the scale, can only be scratched by a diamond, and by no other mineral on the scale, and definitely not by each other, as well — a good reason for you to buy more of your favorite sapphire and ruby jewelry designs.