When it comes to toughness, jade sits at the top of the hardy gemstone list. This might be surprising if you’ve heard that diamonds are the hardest, so which is the strongest? For gemstones, it all comes down to whether a stone is more resistant to scratching or breaking.
Jade has been an important material to humans for millennia with some of the earliest tools in our arsenal being made of jade. Since then, we’ve learned that what was once thought to be a single gemstone actually represents two. Both are pretty resistant to wear, but they do boast different qualities.
One is known as jadeite and it is celebrated for its coloration and translucence, traits that people in the jewelry market will pay top dollar for. It’s rarer and pricier than the other jade gemstone variety, with one 175-tonne lump found in 2016 being valued at $170 million.
Nephrite is the second, and it’s more common and more widely used, probably because it’s the toughest. In fact, when it comes to toughness, nephrite jade is the toughest known natural mineral, tougher even than ceramics and steel.
“This explains why it was used in neolithic times for knife blades, axe heads and later for ornamental carvings,” says Geoscience Australia. “While it is not as hard as some other minerals like diamond, nephrite is made from an interwoven meshwork of fine fibres or needle-like crystals so is not brittle and does not break easily.”
Jadeite jade. Hard, but not quite as tough as nephrite.
So, you can take a piece of jade and shape it into jewelry relatively easily, but it will be very hard to break. By comparison, diamond is incredibly hard to shape, but it’s more likely to break compared to nephrite jade.
In New Zealand, nephrite jade from the South Island is known in Māori culture as pounamu, meaning greenstone. It’s used to create clubs, tools, urns, and ornamental pendants known as hei-tiki that are considered a kind of taonga (treasure), alongside abalone shells that come from one of the world’s few pearl-producing snails.
The greener jadeite is highly valued in China, and most of it comes from Myanmar. They may boast the greenest greens, but they can vary greatly in transparency and color, with a variety of names including imperial green, glassy, and blue-water. The industry is a valuable one, but one that’s dangerous enough to earn these stones the nickname “blood jade” because each year miners are severely injured and killed by landslides within the jade mines.
The ethics of gemstone mining has made global news across all kind of mineral deposits, which has contributed to growing interest in lab-grown alternatives. While some are grown from scratch, which can be energetically expensive, recent achievements have included growing jewellery-quality gems from a “ruby seed”, and even creating glow-in-the-dark crystals.
