My Profile  |  Contact Us  |  Member Portal

American Gem Society Logo

December Birthstones

tanzanite stone

How to Buy Tanzanite

There are many reasons to buy tanzanite, whether to celebrate a December birthday, to commemorate a 24th wedding anniversary, or simply to enjoy the gemstone’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. The cut significantly influences the color, which determines the price. Cutting tanzanite 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 gemstone over a larger violet one.

Most faceted tanzanite weighs less than five carats. Gemstones 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 gems are only found within a few square miles in Tanzania, their price and availability can fluctuate sharply, depending on what happens there.

Although it doesn’t have a long history of admiration like some gemstones, tanzanite didn’t take long to rise through the ranks. Between its exclusive origin, finite supply, and intense blue beauty, tanzanite continues to grow in popularity.

If you are looking for tanzanite birthstone jewelry, find an American Gem Society jeweler near you.

US map

Find a Jeweler

Search for an American Gem Society member jewelry store