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Round tanzanite gemstones featured in diamond halo stud earrings

Tanzanite Guide

Being blue never looked so good. Tanzanite’s signature deep-blue hue rivals that of a sapphire—but its electric shades of silken violet put this gem in a league of its own. Tanzanite has been said to possess symbolic powers that enhance cognitive powers and dissolve stagnancy.
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What is tanzanite?

Tanzanite is a relatively new gemstone with rich blue to lush purple hues. This gem is found in only one place in the world—Tanzania—making it rarer than a diamond. Tanzanite is the birthstone for the month of December and traditionally given as a gift on 24th wedding anniversaries.


  • Reddish Purple
  • Violet
  • Cushion
  • Oval
Rob Lavinsky, – CC-BY-SA-3.0, CC BY-SA 3.0, via Wikimedia Commons / Cropped from original
Optimism, Intuition
6 to 7


Heated or infused to alter color and clarity


Special Gemstone Care: Do not use ultrasonic cleaning and sudden temperature changes.

Similar Gemstones

  • Aquamarine
  • Blue Topaz
  • Sapphire

What to Look for in Tanzanite

Tanzanite is adored for its terrific deep hues. These gems show three distinct colors—reddish purple, blue and violet—depending on what type of light they’re in. This optical phenomenon is called pleochroism. There are several aspects to consider when choosing a tanzanite gemstone.

    Gemstone color is often the most important factor in determining a gemstone’s value. Blue tanzanite is rarer and more highly valued than violet or purple tanzanite, but many people prefer stones with lighter violet hues.
    Learn About Color
  • CUT

    The cut of a gemstone is what gives it symmetry and shows off the stone’s color and brilliance. Because tanzanite is a pleochroic gem, the cut plays a significant part in which color takes prominence in the finished stone.

    Gemstone clarity is determined by any inclusions embedded in the gem, such as gas bubbles, fractures or small crystals. Most tanzanite gemstones have inclusions that are only visible with magnification—and any eye-visible inclusions typically cause a drop in price but don’t necessarily detract from the stone’s beauty. Inclusions aren’t always a bad thing! Rarely, tanzanite contains inclusions that create cat’s eye chatoyancy, a phenomenon where light reflects off the inclusions and produces a luminescent beam, similar to that of a cat’s eye.

    While diamonds are sized and valued by carat weight, gemstone size is based on diameter in millimeters. The size of tanzanite influences its color—large pieces of tanzanite have the finest color, but smaller gems are more abundant.

    Virtually all tanzanite on the market has been heat-treated to bring out the coveted blue to violet hues these gems are prized for. Heat treatments are a permanent, undetectable enhancement and don’t harm the gemstone, but rather add to its allure.

Hardness & Wearability

Tanzanite rates a 6 to 7 on the Mohs scale of hardness, which makes it less durable than harder gemstones like diamonds (10) or sapphires and rubies (9). Tanzanite generally isn’t suitable for intense everyday wear, such as in an engagement ring, unless you choose a protective setting, such as a bezel, channel or pavè setting.

Choosing the Right Tanzanite Jewelry

Violet-blue tanzanite pairs handsomely with cool-toned metals like silver, white gold and platinum.

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Famous Tanzania Gemstones

First unearthed in 1967 in the African country of Tanzania, Tanzanite is one of the newest additions to the colorful world of gemstones. Tiffany & Co. quickly recognized its selling potential and became its main distributor, christening the blue-violet jewels as Tanzanite to highlight the stone’s exclusive geographic origins. Tanzanite may not have the ancient history and fabled virtues of other gemstones, but it’s highly prized for its rare beauty.

How to Care for Your Tanzanite Jewelry

  • Tanzanite gems are dulled by household dust, but with a simple repolish, they’re easily brought back to a like-new luster. Store your tanzanite jewels in a protective cloth bag or jewelry box when you’re not wearing them. Check often for loose or damaged stones, and protect your jewelry from harsh blows.
  • Learn more about caring for tanzanite jewelry in our gemstone cleaning guide — or let us do the dirty work for you with our complimentary gemstone cleaning and repair on all of the jewelry we sell.

Learn More About Gemstones

There’s a galaxy of extraordinary gemstones to discover and admire. Learn more about these phenomenal jewels in our gemstone guide.

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