Tanzanite, Turquoise, Zircon, and Blue topaz(December Birthstones)
Tanzanite, Turquoise, Zircon, and blue topaz are the four birthstones for December. If you had to pick one birthstone, from the blue to bluish purple of tanzanite, to the intense blue and green of turquoise, to the rainbow varieties of zircon, to the intense blue color of blue topaz- there's a color for everyone. If blue is what you are looking for, all four December birthstones have their own unique take on this favorite hue, Whatever your color, style, or budget preferences may be, we can help you pick the right December birthstone for you or a loved one.
# TANZANITE: Tanzanite is a birthstone for December, along with turquoise, zircon, and blue topaz. Tanzanite is also the gem for a 24th wedding anniversary. Tanzanite is relatively new to the colored stone galaxy. This transparent blue gem first turned up in 1967, scattered on the Earth's surface in northern Tanzania, a country in eastern Africa. Scientists identified it as a variety of the mineral zoisite.
Tiffany & Company recognized its potential as an international seller and made a deal to become its main distributor. Tiffany named the gem after the country it came from, and promoted it with a big publicity campaign in 1968. Almost overnight, tanzanite was popular with leading jewelry designers and other gem professionals, as well as with customers who had an eye for beautiful and unusual gems.
Color: Violet blue to bluish violet to violet purple
Refractive Index: 1.691 to 1.700
Birefringence: 0.008 to 0.013
Specific Gravity: 3.35
Mohs Hardness: 6 to 7 on the Mohs scale
Stability: Tanzanite is stable under normal wearing conditions, which means it’s resistant to the effects of heat, light, and common chemicals. Even so, tanzanite should not be subjected to very high temperatures or sudden temperature changes. It can be attacked by exposure to hydrochloric and hydrofluoric acids. Cleaning: Warm, soapy water is always safe. Ultrasonic and steam cleaners are never recommended for tanzanite Treatment and durability considerations: Tanzanite is routinely heat-treated to modify its color from a predominately brownish appearance to a predominately blue to purple appearance. The treatment is stable with no additional durability concerns.
There have been instances where tanzanite was coated to modify the color. Although rarely done, the coatings are not permanent and can be scratched or damaged through normal wear. Like other transparent gemstones, tanzanite can be fracture-filled to improve apparent clarity, although this is an uncommon tanzanite treatment method. The materials used to fill fractures in gemstones can alter in appearance over time.
# TURQUOISE: Turquoise is the traditional for the month of December and the gem of the 11th wedding anniversary. Turquoise is one of the world's most ancient gems. Archaeological excavation revealed that Egyptian royalty wore turquoise jewelry as early as 5500 BC, and Chinese artisans were carving it more than 3,000 years ago. Turquoise is the national gem of Tibet and has long been considered a stone that guarantees health, good fortune, and protection from evil.
Turquoise was a ceremonial gem and a medium of exchange for Native American tribes in the southwestern US. They also used it in their jewelry and amulets.
Chemistry: CuAl6(PO4)4 (OH)8.5H2O
Color: Blue to green
Refractive Index: 1.610 to 1.650
Birefringence: Not detectable
Specific Gravity: 2.76 ( 0.14, -0.36)
Mohs Hardness: 5 to 6 on the Mohs scale
Sources/Origin: China, Iran, and the USA(Arizona or New Mexico)
Stability: Turquoise is generally stable to light, but high heat can cause discoloration and surface damage. It dissolves slowly in hydrochloric acid, and it can be discolored by chemicals, cosmetics, and even skin oils or perspiration. Cleaning: It’s safe to clean turquoise jewelry with warm, soapy water, but it should never be cleaned with steam or ultrasonic cleaners. Some turquoise is treated to improve its surface appearance. Heat or solvents can damage the treated surfaces.
# ZIRCON: Zircon is a birthstone for the month of December, along with Tanzanite, Turquoise, and Blue topaz. Zircon is a beautiful colored stone with its own fair share of folklore and charm. In the middle ages, this gem was thought to induce sound sleep, drive away evil spirits, and promote riches, honor, and wisdom. Zircon occurs in an array of colors. Its wide and varied palette of yellow, green, red, reddish brown, and blue hues makes it a favorite among collectors as well as informed consumers.
Color: Blue, red, yellow, orange, brown, green
High: 1.925 to 1.984 ( /- 0.040)
Medium: 1.875 to 1.905 ( /- 0.030)
Low: 1.810 to 1.815 ( /-0.030)
Birefringence: 0.000 to 0.059 (low to high)
Specific gravity: 3.90 to 4.73
Mohs Hardness: 6 to 7.5 (low to high) on the Mohs scale
Source/Origin: Cambodia, China, Myanmar(Burma), Sri Lanka, Thailand, and Vietnam
Treatment: Zircon is commonly heat-treated to produce blue and colorless varieties. As with any transparent gemstone, zircon can be fracture-filled to improve apparent clarity, but this treatment is rarely applied to this gem.
Stability: Zircon is generally stable when exposed to light, but some heat-treated stones might revert back to their original colors (usually light brown) after prolonged exposure to bright light. Heat can alter the color of some zircon. Zircon is stable when exposed to chemicals. Cleaning: Warm, soapy water is recommended for cleaning zircon. Ultrasonic and steam cleaners are not recommended for cleaning this gem.