Gem toughness: "tough" is not another word for "hard."

As we explored in our previous post, Gem hardness—it matters!, the durability of a gemstone is a very important consideration when purchasing a piece of jewelry. Well, durability includes hardness and toughness, and they are not the same thing.

While hardness is a gem's resistance to scratching and abrading, toughness is a gem's resistance to breaking and chipping. Think of it this way: it's the difference between scratching your car's windshield and shattering it.

A gem's toughness is the result of the strength of its atoms' bonds. Jade is one of the toughest gems there is—it's significantly tougher than diamond—but, paradoxically, it's easier to scratch than emerald and topaz! In fact, jade's toughness is so high that it's been carved into functional weaponry like axe-heads and knife blades for millennia.

Gems that aren't very tough can still be worn as jewelry, but depending on how "not tough" they are, some stones may be better suited to wear in pendants or earrings than as rings or in bracelets. Oftentimes, an appropriate setting can make all the difference: a bezel is a great option for protecting a diamond with a vulnerable, thin girdle... and "V" shaped prongs are a must when it comes to shielding the breakable points of marquise and pear cut stones.