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Beautiful Blue Birthstones for December

Zircon, Blue Topaz, Turquoise

People born in December not only get to enjoy the Holidays in their birthday month, but they get a choice of three beautiful hues of blue gems as their birthstone.

"From medieval times until the 1921 Jewelers of America (JA) Official Birthstone Listing, bloodstone and ruby were considered December birthstones." At the turn of the century, the JA started a color theme with their selection of birthstones, and December's theme was blue. While Zircon does present in a variety of colors, the Blue Zircon is one of the most popular next to the clear, which is reminiscent of diamonds. While many of the blue gems and stones are recognized for their connection to December, blue is still the common denominator. These stones include turquoise, lapis lazuli, zircon, tanzanite and blue topaz. We will focus on the GIA standard, which is the Zircon, Turquoise and Tanzanite.

The zircon, one of the oldest mined gems; the turquoise, mined early in man’s history for jewelry; and the relatively newly discovered tanzanite. These stones are relatively inexpensive, but are no less beautiful.

The Zircon

Zircon Colors

The zircon is a colorless stone that is known for its brilliance and flashes of multicolored light, called "fire". It is close enough to the properties of diamond to account for centuries of confusion between the two gems. However, the Zircon is much softer than the diamond with a Mohs hardness of only 6.5 to 7.5.

Zircon are classified by some gemologist into three types – High, intermediate and low. A zircon’s classification depends on its properties, which are directly related to the amount of radiation-induced damage done to its crystal structure from surrounding rock. Just as one would think, high or normal zircons have full crystal structures, with little or no damage from radioactive elements, whereas low zircons have a great deal of damage and, in extreme cases, are practically amorphous, which means they lack an orderly crystal structure. Most gem quality zircons are of the high classification.

Zircon in its purest form is completely colorless, but owing to impurities, it can occur in a wide range of interesting colors, including yellow, orange, red, green, blue, violet, brown and combinations in between.

There is still disagreement as to where the name Zircon originates. The name Zircon is thought to be derived from the Persian word “zargun” which means “gold-colored.” Some believe it comes from the Arabic word "zarkun' meaning "cinnabar" or "vermilion"

In the middle ages, zircon was said to aid sleep, bring prosperity, and promote honor and wisdom in its owner.

Fun Facts:

  • Zircon sometimes contains traces of uranium, irradiating itself and changing its properties.

  • Colorless zircon is called “Matara” zircon after a city in Sri Lanka near where it is mined.

  • Before the development of lab-created cubic zirconia, the naturally occurring Zircon was often used as a diamond substitute.

  • The zircon is actually the oldest known mineral on Earth; the oldest samples are even older than the moon!

  • For centuries the zircon was confused with diamonds because in it's purest form, the zircon is almost colorless.

The Turquoise

Fine turquoise is only found in dry and barren climates, a very few places on earth. Copper rich groundwater seeps down and reacts with minerals that contain phosphorus and aluminum. This reaction creates the beautiful semi translucent to opaque compound of hydrated copper and aluminum phosphate.. or as we all like to call it.. Turquoise!

The name “turquoise” comes from the French word “turqueise”, meaning “Turkish stone.” This is because it was first transported to Europe via a Turkish nation. The color we recognize as Turquoise is the color of the stone.

Most people associate Turquoise with the southwest American States of New Mexico, Nevada and Colorado. These states are rich in Native American history. However, Turquoise, along with Lapis Lazuli, is one of the oldest known mined gemstones were mined in the Middle East for ages. The most famous mine being in Neyshabur mines

Neyshabur Mines, Iran

in Iran. These stones have been discoverd in decorative jewelry in places such as Ancient Persia, Egypt and Turkey. “Persian Blue” is associated with the color of the turquoise mined in the Neyshabur mine. Persian turquoise has been discovered in ancient graves throughout the Caucasus in the 1st and 3rd century AD. "The Causasus is a mountain system and region lying between the Black Sea (west) and the Caspian Sea (east) and occupied by Russia, Georgia, Azerbaijan and Armenia."

Turquoise is a combination of hydrous phosphate of copper and is fairly soft. It can only

reach a Mohs of 6. Though it is soft, it polishes quite well to a beautiful sheen, and color ranges from blue to green sometimes with flecks of pyrite or veins of dark limonite. Turquoise is most often cut and polished in cabochons and set in silver or yellow gold. This gives the gem the opportunity to show off its interesting colored veins and enhances the color of the stone.

Natural turquoise occurs at botyroidal (grape-like) masses or nodules in fissures. The best quality turquoise is located in Northeast Iran. Turquoise deposits are also found in Afghanistan, Argentina, Australia, Brazil, China, Israel, Mexico, Tanzania and the USA.

Turquoise has a long history of use as a talisman or amulet. The ancient Egyptians, Mesoamericans, Native Americans and Tibetans have believed for centuries in the special healing powers of turquoise. In ancient times it was thought to protect the wearer from harm and others believed it would bring good luck.

In modern times, the turquoise is believed to offer protection and to be helpful for careers and travel. It is also believed to facilitate leadership and enhance clear communications. Medically it is thought to alleviate migraines and create feelings of peace and balance.

Fun Facts:

  • Turquoise buried in ancient Egyptian tombs is some of the world’s oldest jewelry dating back to 4,000BC

  • In 1519, Montezuma, thinking Cortes was Quetzalcoatl, gave him the god’s favorite gem: the Turquoise.

  • Turquoise is colored by copper, which creates some of the most vivid blues and greens in gems.

The Tanzanite

Tanzanite Color Range

The Tanzanite was discovered in 1967 by Maasai herders who found the crystals in the Merelani Hills new Arusha, Tanzania. The blue crystals were first thought to be sapphires, but the color was wrong and the tanzanite only has a 6.5 – 7.0 on the Mohs hardness scale whereas Sapphires are a 9.0. The mines in Tanzania are the only place to find the pure blue–purple gem.

A member of the Zoisite mineral group, trace amounts of vanadium, mixed with extreme

heat, cause the blue color, which ranges from pale blue to intense ultramarine with violet undertones. Officially the tanzanite is a blue zoisite, but Tiffany didn’t like the name and renamed it Tanzanite to highlight its exclusive geographic origin.

Tanzanite ranges in color from ultramarine to sapphire blue. Under artificial light, it may appear more violet. Tanzanite’s pleochroism (two colors) means that it can appear blue or violet when viewed from different angles. The gems are clear and when cut with facets produce the most vivid colors in any light.

Considered to be a spiritual stone that can be used in meditation, the tanzanite is thought to inspire compassion and to encourage calmness. It is helpful in communication and problem solving.

Fun Facts:

  • Tiffany and Co renamed the blue zoisite to Tanzanite because “zoisite” sounded too much like suicide.

  • Tanzanite can only be found in limited supply in the hills of Merelani in northern Tanzania

  • The largest tanzanites were found in 2020 by a Tanzanian miner. The gems weighed in at 46,335 carats and 25.514 carats!

  • Tanzanite exhibits the effect known as Trichroism, showing three colors when viewed from different angles.

So Happy Birthday December! You have a wonderful selection to choose from. Even if you are not born in December, wear these beautiful stones to promote calmness, to protect the traveler, to help you sleep. Remember, you can also say say you are wearing a gem that is older than the moon!

If for no other reason, wear them because they are beautiful!

I hope you have all enjoyed this monthly blog on the birthstones. I will continue with more stones and interesting jeweler facts. Happy Holidays!


The Jeweler’s Directory of Gemstones by Judith Crowe

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