Turquoise – the December Birthstone

December Birthstone 1 - aTurquoise is so versatile. It can take several different, readily recognizable forms, and each one suits a totally different style perfectly. And the history of this stuff is a trip.

Have you ever laid on your back in the grass on a summer day and watched the clouds roll by? The cotton balls drift past on a universally recognized shade of blue. That’s what turquoise is supposed to look like. When the ancients first found turquoise, they thought it was pieces of the sky. So they used it. They used it for decorating walls, ceiling domes, pottery, weapons, tables, tombs, ceremonial objects, you name it: they covered it in turquoise. They even ground it up to use in cosmetics. Turquoise is one of the oldest, purposefully mined gemstones of all time, dating back over 6,000 years to Pre-Dynastic Egypt, spanning four continents and dozens of cultures.

Somewhere around 4,000 years ago, deposits of turquoise that are now referred to as “Persian grade” began to be worked in the mountains of Iran. This turquoise is still considered the best quality in the world. It is robin’s egg to pure sky blue, often free of matrix, and I think it looks great in high-karat gold or oxidized sterling. It’s also compactly and densely formed, so it’s very stable and takes a great polish for a soft mineral.

But sky blue isn’t all there is to it. Turquoise also comes from our neck of the woods. The American Southwest is renowned for its turquoise mines. Over 2,000 years ago, the Olmecs and the Maya imported turquoise from these deposits. In fact, the Ancient Maya held turquoise in such high esteem that no one was actually permitted to own it. All they found was dedicated to their pantheon. Up until the Spanish Conquest, the Toltecs and the Aztecs all imported it from the same sources, as well. The Apache tribes of the Southwest believed turquoise to be a powerful talisman for hunting and war. They would tie turquoise beads to their bows and rifles so their projectiles would fly directly to the intended target.

Nevada, Arizona, New Mexico, and Colorado are all sources of turquoise in the US, but Nevada has more mines than the other three states combined. Turquoise from these locations differs from Iranian material; it’s more chalky and porous, but most of it is pretty stable. It tends to grow in thin veins, so most pieces feature lots of matrix. It also trends to greener tones because of richer copper deposits in the area (copper is what colors turquoise). Some of it is even bright tropical green, which looks really cool in yellow gold.

Due to the way turquoise grows, it is sometimes impossible to harvest just the gemmy material, so the surrounding rock is cut away with it. This host rock is referred to as “matrix.” It can vary in color and composition depending on the location from which it was retrieved. You’ll see it as black or brown veins running through the turquoise. This is where turquoise can take on some serious character. I’ve got a cuff bracelet with a piece of turquoise that looks like a river flowing around and through a sandbar. Matrix totally shifts the beauty of turquoise from uptown sleek to Bohemian chic.

All turquoise has one major drawback: compared to some other gems, it’s fragile. Turquoise is not what I would call hard-wearing. It’s fairly soft, so no rough stuff. You have to treat it as you would pearls; it needs to be the last thing you put on. It’s sensitive to chemicals, and if it’s porous, it will absorb liquids that can harm it. Hairspray and perfume can discolor turquoise over the years. Certain household cleaners can actually dissolve turquoise. No dips in the pool or hot tub, either (that’s actually really bad for all jewelry).

But don’t let any of that spook you. As a rule, I steer clear of material that’s too unstable or has been treated to be stable. The highest grades of turquoise have a very compact structure; that’s what I seek out. Turquoise is coated in a thin layer of either paraffin or beeswax. The clear wax coating fills any microscopic porosity (even in the highest-grade material), offering a little extra protection against accidental exposure to harmful chemicals.

Posted in: Custom Jewelry, December Birthstones, Fine Custom Jewelry, Jewelry Trends, Marc Aronstam

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