December Birthstones- Tanzanite, Zircon, and Turquoise

December Birthstones- Tanzanite, Zircon, and Turquoise

December also gets a variety of birthstones which include zircon, turquoise, and tanzanite.  

Zircon is another personal favorite of mine. Zircon is not cubic zirconia, the zircon we are talking about is a natural stone, not the manmade synthetic diamond simulant cubic zirconia. However, colorless zircon does make for a great alternative to a diamond because of its extreme brilliance and fire, however you do need to take special care of it because of its brittleness.  

Zircon comes in an array of colors including: colorless, brown, blue, yellow, green, reddish browns. Colorless and blue zircon are both a result of heat treatment, however can be found in nature, but it’s very rare. The heat treatment is usually stable and undetectable.

Zircons are found in places such as Madagascar, Cambodia, Vietnam, Australia, Myanmar, and Sri Lanka. 

The Basics:

  • Mohs Scale: 6-7.5
  • Mineral: Zircon

Photo: GIA.edu

Turquoise is also one of December’s birthstones and one of its first. Turquoise varies in color from yellows, to greens, blues, and greys, however the most sought after color is a very uniform colored “robin’s egg” blue.

Turquoise is incredibly porous and because of this in its completely natural state can be very unstable. Treatments using oils or polymer plastics to “seal” the turquoise are commonly used and this is called “stabilized turquoise.”

The United States, China, Egypt, and Chile are the most common places where turquoise is mined currently. Historically, Persia produced large amounts of top quality turquoise. Turquoise is commonly imitated, so be on the lookout for pieces that look too good to be true with a price to match!

The basics:

  • Mohs Scale: 5-6
  • Mineral: Turquoise
  • 11th wedding anniversary

 Tanzanite was added as a birthstone of December in the recent past. Prior to its discovery in 1967, the only form of zoisite that was known was the opaque green variety. Tanzanite is extremely pleochroic meaning that you can see different colors at different angles, so cutters need to take this into consideration when fashioning stones. The finest tanzanite can resemble sapphire in its beautiful blue hues. Mostly you will see tanzanite in violet-violet blue colors.

Tanzanite is routinely heated, about 95% of the blue material on the market has been heat treated. Tanzanite is commercially mined in one place in the world, Tanzania; this causes prices to fluctuate due to availability.

Tanzanite requires special care due to its lack of toughness and it is very sensitive to temperature changes.

 The Basics:

  • Mohs Scale: 6-7
  • Mineral: Zoisite
  • 24th wedding anniversary

 

Photo: GIA.edu

Fun Facts:

  • Radioactive impurities in zircon cause its crystal structure to break down (don’t worry, the effects are long gone by the time you’re wearing it)
  • Zircon is thought to keep away evil spirits during sleep
  • Zircon is the oldest mineral on earth at 4.4 billion years old
  • Most tanzanite starts out as a brownish color
  • Tiffany & Co. named Tanzanite after the location it was discovered
  • Turquoise has been uncovered in Ancient Egyptian ruins making it one of the oldest gemstones used
  • Turquoise is the national gem of Tibet
  • The Appaches believed that if you attached a piece of turquoise to an arrow, it would improve its accuracy