Tanzanite Gemstone – Colors, Pleochroism, Origin, and Value

Tanzanite is one of the world's most extraordinary gemstones, captivating with its intense blue, elegant violet, and spectacular pleochroism. Its unique color effect and its origin limited to a single deposit make it one of the most coveted colored gemstones.

Tanzanite is the blue-violet variety of the mineral Zoisite and was only discovered in Tanzania in 1967. Despite its relatively young history, it has developed into one of the most well-known and popular gemstones in the world within a few decades.

Its pronounced pleochroism is particularly fascinating. Depending on the viewing angle, intense blue tones, violet nuances, and occasionally slightly reddish or grayish-blue color areas can be seen within the same stone. Hardly any other gemstone shows a comparable interplay of color, light, and perspective.

Since tanzanite occurs exclusively in a small area at the foot of Kilimanjaro, it possesses a special rarity. Its combination of unique origin, spectacular color, and limited supply makes it equally attractive to collectors, jewelry lovers, and gemstone enthusiasts.

Directly to our Tanzanite gemstones in the shop

What is Tanzanite?

Tanzanite is the blue to violet variety of the mineral Zoisite.
Chemical composition: Calcium-Aluminum-Silicate (Ca₂Al₃(SiO₄)₃OH).
Its exceptional color is created by vanadium in the crystal lattice – enhanced by natural or artificial heat.

Special Properties of Tanzanite

Tanzanite displays a play of color unlike any other gemstone – a harmonious interplay of blue and violet.

unique blue-violet
strong pleochroism → shows blue, violet & burgundy depending on the viewing angle
high transparency
noble vitreous luster
good hardness (6–7) → suitable for jewelry
only one deposit worldwide → extreme geological peculiarity

Colors & Varieties of Tanzanite

Tanzanite offers a unique spectrum of intense gemstone colors:

Deep Blue Tanzanite
The most valuable variety. Dark blue with a violet undertone → very rare & high-priced.
Royal Blue Tanzanite
Intense, luminous blue with a slight purple. The "classic" premium tanzanite.
Violet Tanzanite
Elegant violet with a blue shimmer. Particularly popular with collectors.
Lavender Tanzanite
Delicate pastel nuances. Ideal for modern jewelry designs.
Untreated Tanzanite
Mostly brownish or greenish – less colorful, but collectible.

Origin of Important Tanzanites

Tanzanite has only one deposit worldwide:

Tanzania – Merelani Hills (at Kilimanjaro)
A geologically unique area divided into four "blocks" (A–D). The best qualities traditionally come from:

Block C & D
This exclusive origin status makes Tanzanite one of the rarest gemstones in the world.

Treatment of Tanzanite

Almost all tanzanites are heat-treated (heating). Untreated, naturally blue-violet tanzanites are extremely rare.

intensifies the blue
removes brownish or greenish undertones
stable & accepted in the industry

Value Factors of Tanzanite

1. Color

The most important factor:

deep blue → highest value class
blue-violet mix → highly coveted
too pale → low value

2. Clarity

Tanzanite is usually very clear.

eye-clean → particularly valuable
slight inclusions → acceptable
many inclusions → significantly lower quality

3. Cut

A good cut maximizes:

play of color (pleochroism)
light reflections
depth effect

Typical cuts are: Oval, Cushion, Pear, Emerald Cut.

4. Size

Tanzanite forms large crystals:

5–10 ct → very sought after
10–20 ct → impressive & high-priced
over 20 ct → rare in top color

Is Tanzanite a good gemstone for collectors?

Yes – and particularly coveted. Tanzanite is one of the most important colored gemstones of our time.

Reasons:

only one deposit worldwide
intense, unique play of color
strong demand in the luxury jewelry market
attractive value stability
iconic gemstone color

Tanzanite in Macro Art

An ideal gemstone for macro art in acrylic, aluminum, and 3D – especially for elegant color combinations. Tanzanite is spectacular under macro photography: