December Birthstones

December Birthstones



Turquoise is one of three birthstones for the month of December (the other two December birthstones are tanzanite and blue zircon). T urquoise has been prized by cultures all over the world for over 5,000 years. Turquoise is a semi-translucent to opaque gem that ranges from blue to green and often has veins of matrix (remnants of the rock in which it formed) running through it.

Turquoise has been mined in the Nishapur district of Iran for more than 1,000 years. The prized even-colored, intense blue turquoise from this region is dubbed “robin’s egg blue,” “sky blue” and “Persian blue.” Trade professionals now use these terms to describe turquoise of this color – regardless of the source.

Although New Mexico was the largest producer of turquoise in the U.S. until the 1920s, today most of the U.S. production of this December birthstone comes from Arizona and Nevada. Mines have names like Dry Creek, Easter Blue, Emerald Valley and Fox. The Kingman mine in Arizona is a historically important source that is known for producing intense blue turquoise. Now closed to turquoise mining, Arizona’s Sleeping Beauty mine was a prolific producer for more than four decades. Today, China is the world’s largest producer of turquoise. Hubei Province, in central China, is the source of most of the gem-quality turquoise currently being mined there.

Turquoise has a Mohs hardness of 5-6. Turquoise is often treated to improve its durability, appearance and polish. Turquoise can be dyed or chemically enhanced by adding an epoxy or acrylic resin for greater hardness or better color.

Turquoise is generally stable to light, but high heat can cause discoloration and breakage. Turquoise can be damaged by acids, and it can be discolored by certain chemicals, cosmetics and even skin oils or perspiration.   


Tanzanite is a rare gemstone often described as “velvety” because of its deep and saturated blue and violet colors.

What makes Tanzanite so special?
Tanzanite is one of only two known gemstones that clearly exhibits two colors at once. Tanzanite shows different colors when viewed in different directions – gently rock and tilt your tanzanite to reveal the play and flash of colors as the angle of the stone changes. Colors change from blue to violet and some tanzanite will flash a burgundy color. Cool lighting --like daylight equivalent fluorescent --will emphasize tanzanite's blue, while warm lighting --like incandescent --will make it appear more violet.

Where does Tanzanite come from?
A Masai tribesman Ali Juuyawatu is credited with finding the first tanzanite crystal in 1967. The Merelani Hills of northern Tanzania is the only place on earth where tanzanite is mined commercially. North of the mines tower the snow-covered slopes of Mount Kilimanjaro.

How Should Tanzanite Be Worn?
Tanzanite has a hardness of 6 to 7 so it can be abraded by harder materials. The wearer just needs to be aware of the stones' “softness” and be cautious of rough wear and hard knocks. Heavy work such as gardening, household chores and trips to the gym should be avoided in your Tanzanite.

Tanzanite is resistant to everyday heat, light and most common chemicals but avoid extreme heat, intense light and harsh chemicals. Protect tanzanite from sudden temperature changes.

Is Tanzanite Heat Treated?
Yes! Tanzanite is routinely heated to bring out Tanzanite’s lovely colors. The blues and violets that Tanzanite is so well known for do not emerge until the stone is heated. The heating process removes the brown / burgundy axis, leaving just the blue and violet axis. This treatment is stable, permanent and durable.

How Do I Clean Tanzanite?
Warm, soapy water is the best way to keep your Tanzanite clean, using a soft toothbrush to gently clean around prongs and under the stone. Rinse well so the soap does not dry and dull the stone. Use a soft cloth to remove fingerprints from the top of your stone. Avoid Ultrasonic and Steam Cleaning machines. They use high frequency vibration and high heat to clean the stones which might affect your Tanzanite.

How Do I Store Tanzanite?
Store your Tanzanite in a box, bag or pouch to prevent jewelry from rubbing against each other which may scratch your Tanzanite. This includes pairs of Tanzanite earrings. A velvet or flocked lined jewelry box with compartments that separates your jewelry is perfect.


Zircon is one of the birthstones for December (other December birthstones are turquoise and tanzanite). Zircon gemstone colors are red, orange, yellow, brown, green and blue. Colorless zircon is known for its brilliance and flashes of multicolored light called fire. The sparkle of zircon is second only to diamond. 

Zircon is often located near sapphire sources. In addition to Sri Lanka and Australia which are major producers, countries where the two gems overlap include Myanmar, Vietnam and Cambodia.

Zircon ranges from 6 to 7.5 on the Mohs scale of hardness. It is commonly heat treated to produce blue and colorless varieties, as well as orange, yellow and red. The gem is generally stable when exposed to light, but some heat-treated stones may revert to their original colors (usually light brown) after prolonged exposure to bright light. Exposure to heat can alter the color of some zircon. 

Because zircon tends to abrade, it is best to avoid wearing it in rough conditions, such as while gardening, playing sports or doing dishes.

Don’t be confused by the name. Zircon is a natural, magnificent, and underrated gemstone that has been worn and treasured since ancient times. It’s not cubic zirconia.