In our June Auction, lot 321 is a loose octagonal step-cut tanzanite of 8.77 carats provided with certificate.
Introduction to Tanzanite
Tanzanite is one of the most mesmerising and rare gemstones in the world, prized for its rich blue-violet hues and unique geological origins. First discovered in the foothills of Mount Kilimanjaro in northern Tanzania in 1967, Tanzanite is found in only one location globally, making it approximately 1,000 times rarer than diamonds.
The Origins of Tanzanite
Tanzanite is a variety of the mineral zoisite and owes its name to its country of origin, Tanzania. The gemstone was introduced to the global market by Tiffany & Co., who named it "Tanzanite" and launched an extensive marketing campaign, positioning it as “the most beautiful blue stone to be discovered in 2,000 years.”
Colour and Appearance
Tanzanite’s colour ranges from deep royal blue to vibrant violet and indigo, with pleochroic properties—meaning it can display different colours when viewed from different angles. The most prized Tanzanites are those with a vivid blue hue, similar to that of sapphire, especially in stones over 5 carats. Smaller stones often show more of the violet tones.
How Tanzanite Is Formed
Tanzanite formed around 585 million years ago under unique conditions involving extreme heat and tectonic activity. The gem's formation required vanadium-rich minerals and specific geological pressures, which is why Tanzanite has only been found in a single 4km strip near Mererani, Tanzania.
Rarity and Value
Tanzanite is considered a thousand times rarer than diamonds due to its limited geographic source. Experts believe that the Tanzanite deposit could be depleted within a generation, making this gem not only rare but also a potential investment.
Tanzanite as a Birthstone
Tanzanite was added to the official birthstone list in 2002 as the December birthstone, alongside turquoise and zircon. Its unique colour and rarity make it a popular choice for meaningful gifts and milestone celebrations.
Cut and Clarity
Tanzanite is typically cut in ways that maximise its colour and brilliance. Oval, cushion, and emerald cuts are among the most popular. High-quality Tanzanite is usually eye-clean, with minimal inclusions. The cutting process is delicate due to the stone’s relatively low hardness.
Durability and Care
With a hardness rating of 6 to 7 on the Mohs scale, Tanzanite is softer than many other popular gemstones and should be worn with care. It’s best suited for earrings, pendants, or occasional-wear rings. Clean Tanzanite with warm soapy water and a soft brush—avoid ultrasonic or steam cleaners.
Buying Guide
When purchasing Tanzanite, consider the “Four Cs”:
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Colour: Rich, saturated blue to violet hues are most valuable.
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Clarity: Eye-clean stones are preferred.
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Cut: Quality of the cut enhances brilliance and colour.
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Carat Weight: Larger stones often exhibit deeper colours.
It’s also wise to purchase from reputable jewellers who provide certificates of authenticity, especially given the gem's rarity.
Tanzanite in Jewellery
Tanzanite is increasingly popular in engagement rings, pendants, earrings, and bespoke jewellery pieces. Its striking colour pairs beautifully with white metals such as platinum or white gold, and it also complements rose gold for a warmer aesthetic.
Symbolism and Meaning
Tanzanite is often associated with transformation and spiritual awakening. Many believe it enhances intuition, communication, and emotional clarity. It is also thought to inspire calmness and reduce stress.
Sustainability and Ethical Sourcing
As demand for Tanzanite grows, ethical mining practices have become essential. Many jewellery companies now ensure that their Tanzanite is responsibly sourced, supporting local Tanzanian communities through fair labour practices and sustainable development initiatives.
Conclusion
Tanzanite is not just a beautiful gemstone—it’s a story of rarity, discovery, and natural wonder. Whether you’re drawn to it for its breathtaking hues, its rarity, or its symbolic meaning, Tanzanite is a stunning and meaningful choice for any jewellery collection.
