Tanzanite Gemstone Guide

Tanzanite gemstones are found in the shadows of the majestic Mount Kilimanjaro in Tanzania, the only commercial source for the gemstone. In 1967, a Masai tribesman discovered the gem. It was eventually named tanzanite in honor of its country of origin. The gemstone is often described as “velvety,” mostly because of its deep and saturated color, which ranges from purplish blue to a pure blue.

Tanzanite is a variety of the mineral species zoisite, and is found in nature as colorless, brown, pink or green.

Tanzanite is a December birthstone.

Color

Tanzanites range from lush blues, vibrant violets and rich purples.

Cut

Tanzanites can be cut into many different shapes. Some tanzanite gemstones are carved or sculpted by famous lapidary artists.

Origin

Tanzanites are only found in one place on earth, Tanzania near Mount Kilimanjaro.

Durability

Tanzanite has a hardness of 6.0-7.0 on the Mohs Hardness Scale.

Treatments

Most tanzanite is routinely heat treated, which causes a change of color in the rough material from brown, purple or grey to shades of blue and violet. Any treatments should be disclosed to the buyer.

Lab-Created

There are no lab-manufacturers of tanzanite, though it could be simulated with other materials. This information should be disclosed to the buyer.

Care & Cleaning

• Tanzanites are somewhat delicate and should be worn with care.
• To minimize scratching and wear, store each piece of fine jewelry separately in a soft cloth or padded container.
• Tanzanites should never be exposed to very high heat or wide changes in temperature, put in an ultrasonic cleaner, or steam-cleaned.
• The safest way to clean tanzanite jewelry is to use warm, sudsy water and a tightly woven microfiber or other soft cloth.
• Take all your fine jewelry to a professional jeweler at least twice a year for a thorough cleaning and inspection.

Find Tanzanite pieces at a trustworthy, JA Member Jewelry store in our Find a Jeweler directory.

Content © GIA. Image © Robert Weldon/GIA