Celebrate with sky-blue turquoise, December’s birthstone

Turquoise is as blue as the sky and old as history. It’s been found in ancient Egyptian tombs and has been honored as a holy stone and good luck charm in cultures from Persia, Rome, and North, Central, and South America. It has been used as a form of currency in Native American tribes as well as a talisman carved into fetishes and jewelry.

What gives turquoise its color

According to the GIA, “turquoise is found in only a few places on earth: dry and barren regions where acidic, copper-rich groundwater seeps downward.” Turquoise can be found in a range of shades of blue from bright sky blue to grey-green. The blue comes from copper, the green tones from iron, and chrome can add the grayish tinge.

Turquoise matrix

The veins found in turquoise are called a “matrix.” They’re basically the rock that the stone is found in. They can appear as dark spider webs or spots on the stone. Stones without a matrix tend to be more expensive, but for many people, it adds character and depth to the gem.

What you should know about turquoise jewelry

• Turquoise isn’t cut in facets; it’s cut into cabochons or beads or carved.
• The value of a stone is a combination of its lack of matrix, the brightness of its color, and its texture.
• The stone’s color may get lighter if it’s worn for long periods of time.
• The most valuable stones are a bright blue, called “robin’s-egg blue.”
• Because they’re sensitive, most turquoises are treated in one way or another. Some are hardened with wax or synthetic resin.
• Some stones are artificially colored; you should be informed of this before you purchase one.

Taking care of your turquoise jewelry

• Turquoise ranks 6 on the Mohs hardness scale, which means that it’s softer than quartz.
• You should protect your turquoise jewelry from cosmetics as well as from heat.
• Be careful not to scratch the stone; don’t store it with harder jewels.
• You can clean turquoise with a soft cloth.

Happy December birthday! As the days shorten, wear your turquoise and keep a bit of the bright sky near you. And if I can help you with appraising your turquoise or any other valuable, let me know.

Brilliantly yours, Aimee