Tanzanite Jewelry Guide: The Rare Blue-Violet Gemstone

Tanzanite is one of the rarest gemstones on Earth, found in only one location worldwide — a small area near Mount Kilimanjaro in Tanzania. Discovered in 1967, tanzanite has rapidly become one of the most sought-after colored gemstones, prized for its extraordinary violet-blue color that cannot be replicated by any other natural stone.

What Makes Tanzanite Unique

Tanzanite is a variety of the mineral zoisite, colored by trace amounts of vanadium. What truly sets tanzanite apart is its remarkable trichroism — the ability to display three different colors (blue, violet, and burgundy) when viewed from different angles. This optical property gives tanzanite a shifting, dynamic appearance that changes with viewing angle and lighting conditions.

Understanding Tanzanite Quality

Color

The most valued tanzanite color is a vivid, saturated violet-blue — often described as "royal blue" with violet flashes. The stone should display strong color from all viewing angles. Lighter tanzanites with more lavender or gray tones are more common and less expensive. Color is the single most important factor in tanzanite value.

Clarity

Fine tanzanites are typically eye-clean. Because tanzanite forms in limited geological conditions, stones with good clarity are expected at higher quality levels. Heavily included specimens have significantly reduced value.

Cut

Cutting is especially important for tanzanite because the cutter must orient the stone to maximize the desirable blue-violet color. Skilled cutting can transform a mediocre rough stone into a vivid, deeply colored gem. Oval, cushion, and emerald cuts are most common.

Carat Weight

Tanzanite is available in a wide range of sizes, but large stones with deep color are increasingly rare as the single mine's deposits are gradually depleted. Stones over 5 carats with excellent color command significant premiums. For context on gemstone sizing, see our carat weight guide.

Tanzanite Rarity and Investment

Unlike most gemstones, tanzanite has a single source that will eventually be exhausted. Geologists estimate the mine may be depleted within the next 20-30 years, making tanzanite a truly finite resource. This rarity has led many collectors to view tanzanite as both a beautiful gem and a potential long-term investment.

Tanzanite vs Other Blue Gemstones

• Blue Sapphire: Harder and more durable (9 vs 6.5 Mohs), with a pure blue color. Sapphires are more suitable for daily-wear rings, while tanzanite is better for earrings, pendants, and occasional-wear rings.
• Aquamarine: Lighter blue, more durable. Aquamarine has a calm, watery quality while tanzanite is more dramatic and vivid.
• Blue Topaz: more accessible and available in larger sizes, but lacks tanzanite's unique violet flashes and rarity.

Tanzanite as a Birthstone

Tanzanite was added as a December birthstone in 2002, joining turquoise and zircon. It is also the gemstone for the 24th wedding anniversary.

Caring for Tanzanite

Tanzanite requires more careful handling than sapphires or diamonds due to its lower hardness (6-7 Mohs) and sensitivity to temperature changes. Clean gently with warm soapy water — never use ultrasonic or steam cleaners. Avoid sudden temperature changes, which can cause cracking. Tanzanite is best for earrings, pendants, and brooches rather than everyday rings. For complete care guidance, visit our gemstone care guide.

Explore our tanzanite collection and read our complete buying guide for expert advice.