December Birthstones…

Zircon, Tanzanite, Turquoise

Tanzanite, Zircon or 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.

The zircon, one of the oldest minded 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

Rough Zircon

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

Zircon Colors

range of interesting colors, including yellow, orange, red, green, blue, violet, brown and combinations in between.

The name Zircon is thought to be derived from the Persion word “zargun” which means “gold-colored.”

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!

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!

Native American Turquoise

Turquoise is most known to come from the southwest American States of New Mexico, Nevada and Colorado rich in Native American history. However, Turquoise, along with Lapis Lazuli, is one of the oldest known mined gemstones that have been mined in the Middle East for ages. The most famous mine being in Nishapor in Iran and has been used for millennium in decorative jewelry in places such as Ancient Persia, Egypt and Turkey. “Persian Blue” is associated with the color of the

Persian Blue Turquoise

turquoise mined in the Nishapor mine. Persian turquoise has been discovered in ancient graves throughout the Caucasus in the 1st and 3rd century AD.

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.

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.

Chinese Turquoise

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 Ring

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 still the only place to find the pure blueish – purpleish 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 plechroism 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.
  • Tanizanite can only be found in limited supply in the hills of Merelani in northern Tanzania
  • The largest tanzanite found was discovered on August 6, 2015 weighing in at approximately 16,389 karats!

So Happy Birthday December! You have a wonderful selection to choose from. If you are not born in December, wear these beautiful stones to promote calmness, to protect the traveler, to help you sleep or to 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 facts. Happy Holidays!



The Jeweler’s Directory of Gemstones by Judith Crowe


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