December’s birthstones offer three ways to fight the winter blues: tanzanite, zircon, and turquoise – all of them, appropriately, best known for beautiful shades of blue.
These gems range from the oldest on earth (zircon) to one of the first mined and used in jewelry (turquoise), to one of the most recently discovered (tanzanite).
All of these stones are relatively inexpensive, but their beauty rivals even precious gems. Colorless zircon is a convincing replacement for diamond, tanzanite often substitutes sapphire, and turquoise is unmatched in its hue of robin’s egg blue.
Whatever your style preference or budget, one of December’s three birthstones will match your true blue desires.
HOW TO BUY TANZANITE
There are many motivations to buy tanzanite, whether to celebrate a December birthday, to commemorate a 24th wedding anniversary, or simply to enjoy the gem’s rare, vibrant blue. It even serves as a less expensive substitute for sapphire.
Most tanzanite on the market today gets its blue color from heat treatment, which minimizes the stone’s natural brown hues. Treated tanzanite has become the norm, so although it’s undetectable, it’s usually assumed.
Generally, tanzanite follows the same value parameters as diamonds.
Color, of course, is tanzanite’s most prized trait, especially when it’s deeply saturated blue with violet hues. Paler shades are less expensive.
Tanzanite is pleochroic, which means it displays different colors from different angles. So the cut significantly influences the color, which determines the price. Cutting a stone to emphasize the blue may waste more of the rough, but because this color is more valuable than violet, the cutter may choose a small fine-colored blue gem over a larger violet one.
Most faceted tanzanite weighs less than five carats. Stones heavier than 50 carats are rare, although The Smithsonian Institution’s collection includes a faceted 122.7-carat tanzanite. The world’s largest rough tanzanite weighed 16,839 carats.
Because tanzanite is only found within a few square miles in Tanzania, its price and availability can fluctuate sharply, depending what happens there.
Although it doesn’t have a long history of admiration like some gems, tanzanite didn’t take long to rise the ranks. Between its exclusive origin, finite supply, and intense blue beauty, tanzanite continues to grow in popularity.
Tanzanite is the exquisite blue variety of the mineral zoisite that is only found in one part of the world. Named for its limited geographic origin in Tanzania, tanzanite has quickly risen to popularity since its relatively recent discovery.
Zoisite had been around more than a century and a half before this rare blue variety was found in 1967. Trace amounts of vanadium, mixed with extreme heat, cause the blue color – which ranges from pale blue to intense ultramarine with violet undertones.
Due to pleochroism, tanzanite can display different colors when viewed from different angles. Stones must be cut properly to highlight the more attractive blue and violet hues, and deemphasize the undesirable brown tones.
The majority of tanzanite on the market today is heat treated to minimize the brown colors found naturally and to enhance the blue shades that can rival sapphire.
Tanzanite is still only found on a few square miles of land in Tanzania, near majestic Mount Kilimanjaro. Its price and availability are directly tied to mines in this region.
Tanzanite measures 6.5 to 7 on the Mohs scale of hardness – which is not nearly as hard as the sapphire it often substitutes. Given its vulnerability to scratch during daily wear and abrasion, tanzanite is better suited for earrings and pendants than rings.
Between its deep blue color and its limited supply, tanzanite is treasured by many – whether one is born in December or not!