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Tanzanite

Poised between lush blue, vibrant violet, and rich purple, exotic tanzanite is found in only one place on earth, near majestic Mount Kilimanjaro.

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Unique Hues

Unique violet-to-blue hues

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Pure Blue

Tanzanite's rich hues rival sapphire's beauty.

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Pleochroism

Tanzanite's color blends blue hue and violet pleochroic hues.

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Tanzanian Beauty

This beautiful Merelani tanzanite crystal measures 4 x 2.9 cm.

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Pleochroic Colors

This crystal shows strong blue and brownish green pleochroic colors.

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Matrix

This crystal shows traces of the rock where it grew on its base.

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Tools

Buyer's Guide

Fine tanzanite’s strong pleochroism and intense violet-to-blue face up colors help identify the gem and provide a large part of its value. Paler colors are more commonly found and less valued. Eye visible inclusions also cause a drop in value.

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What To Look For

Color

Due to tanzanite’s strong pleochroism, each fashioned gemstone usually displays a mix of both blue and violet hues depending on viewing angle. The majority of tanzanites mined are light to medium purple and blue colored stones. However, the gem is generally famed for the small number of intensely saturated, bluish-violet stones which usually occur in sizes above 5 carats.

Clarity

Eye-visible inclusions decrease the value of tanzanite, particularly in lighter colored stones, where they’re more visible against the gem’s bodycolor. Any inclusions that might pose durability problems—such as fractures—lower tanzanite value greatly.

Cut

Tanzanite is available in a wide range of shapes but cushions, trillions and oval cuts are most common. Cutting orientation can emphasize which colors are seen through the gem’s crown. Cutting to display a gem’s violet color face up usually retains more carat weight from the rough than fashioning it to display a predominantly blue hue.

Carat Weight

Tanzanite is available as fine, larger pieces with strong color or lighter material cut to standard sizes for use in mass market jewelry. Tanzanite color is less saturated in smaller sizes. Gems must be above 5-cts. in size to have deep, fine color.

Tanzanite Quality Factors: The Comprehensive Guide

Tips & Advice

1. Size and color are related.

Tanzanite usually has to be larger than five carats to reach a deep saturated violetish blue or bluish violet color. Small accent stones less than two carats in size are commonly a lighter color.

2. Consider a protective setting.

With a hardness of 6 to 7, tanzanite is softer than many gems. Exercise a little caution with tanzanite rings. A setting that surrounds the tanzanite with metal or gems will help protect it.

3. Don’t compromise on cut.

The quality of the cut can make a big difference in beauty and brilliance. Your tanzanite should sparkle in a lively way, reflecting light back evenly across the entire gem. Poorly cut gems are much less marketable and sell at a discount.

4. Work with a knowledgeable jeweler.

Because tanzanite is an unusual gem, make sure you choose a jeweler who has gemological knowledge and expertise. A jeweler who knows and loves tanzanite should have a selection to show you so you can see quality differences side by side.