Tanzanite
Tanzanite is one of the rarest gemstones on earth, found in just one location — a small area near Mount Kilimanjaro in Tanzania. Discovered only in 1967, it captivates with its rich violet-blue colour and strong pleochroism, showing different colours from different angles.
Quick Facts
Colour
Rich violet-blue, often shifting between blue and violet depending on the viewing angle (pleochroism).
Hardness
6 to 7 on the Mohs scale.
Origins
Found exclusively in the Merelani Hills of the Manyara Region, Tanzania, near Mount Kilimanjaro.
Lustre
Vitreous lustre with strong pleochroism — tanzanite shows different colours (blue, violet, and burgundy-brown) when viewed from different crystal directions.
What is Tanzanite?
Tanzanite is a blue-violet variety of the mineral zoisite (calcium aluminium silicate). It was discovered by Maasai herders who noticed brilliant blue crystals on the ground near Merelani Hills in northern Tanzania, reportedly after a lightning strike set fire to the surrounding grassland. Tiffany & Co. recognised its commercial potential and introduced it to the world in 1968, naming it "tanzanite" after its country of origin. Tanzanite's supply is finite — it comes from a single deposit roughly 7 kilometres long and 2 kilometres wide, and geological estimates suggest the mine could be exhausted within the next few decades.
Properties
Colour
Rich violet-blue, often shifting between blue and violet depending on the viewing angle (pleochroism). In daylight, tanzanite leans blue; under incandescent light, it appears more violet. The most valued tanzanite displays a vivid, saturated blue-violet.
Hardness
6 to 7 on the Mohs scale. Softer than sapphire and requiring more careful handling, particularly in ring settings where it is exposed to daily wear.
Origins
Found exclusively in the Merelani Hills of the Manyara Region, Tanzania, near Mount Kilimanjaro. There is no other known source of gem-quality tanzanite anywhere in the world.
Lustre
Vitreous lustre with strong pleochroism — tanzanite shows different colours (blue, violet, and burgundy-brown) when viewed from different crystal directions. Most tanzanite is heat-treated to enhance the blue-violet colour and minimise the brown axis.
Varieties
Tanzanite's colour varies primarily in saturation and tone. Vivid, deeply saturated blue-violet stones are the most valuable. Lighter tanzanites display a softer lavender-blue that has its own appeal at more accessible prices. Some untreated tanzanite shows a trichroic colour — blue, violet, and brownish-red visible from different angles. Rare "chrome tanzanite" (actually chrome-bearing zoisite) displays a vivid green colour. Large tanzanite crystals do exist, with exceptional specimens reaching over 100 carats.
History
Tanzanite's discovery story is remarkably recent. In 1967, Maasai cattle herders in northern Tanzania found blue crystals on the ground near the Merelani Hills. Local prospector Manuel d'Souza initially thought they were sapphires but sent samples for analysis. Geologists identified them as a new variety of zoisite. Henry B. Platt, the great-grandson of Louis Comfort Tiffany and president of Tiffany & Co., recognised the stone's potential and orchestrated its market introduction, naming it "tanzanite" rather than "blue zoisite" for commercial appeal. The strategy worked — tanzanite became one of the most popular coloured gemstones within a generation.
Meaning & Symbolism
Tanzanite symbolises transformation, spiritual awareness, and new beginnings. As one of the newest gemstones to enter the market, it represents the excitement of discovery and the value of rarity. It is thought to stimulate intuition, raise consciousness, and promote a deeper understanding of oneself. Tanzanite's colour-changing nature is sometimes interpreted as a reminder to see situations from multiple perspectives.
How to Care for Tanzanite
Tanzanite requires more careful handling than harder gemstones. Clean only with warm soapy water and a soft cloth — never use ultrasonic or steam cleaners, as tanzanite is sensitive to sudden temperature changes and can crack. Avoid hard impacts. Remove tanzanite rings during physical activity, housework, or manual tasks. Tanzanite is better suited to earrings and pendants for everyday wear, with rings reserved for special occasions or worn with care. Store separately from harder gemstones.
Tanzanite Jewellery Ideas
Tanzanite's rich violet-blue makes it a stunning centre stone for statement rings and pendants. Its colour looks exceptional in white gold or platinum with diamond accents. Tanzanite earrings — particularly studs and drops — are an excellent way to enjoy the stone daily without the risk of ring wear. A large tanzanite pendant on a delicate chain creates an eye-catching focal point. Given the stone's finite supply, tanzanite holds particular appeal for collectors and those who value rarity.