Tanzanite Description:

Tanzanite is a rare and highly prized gemstone known for its striking blue-violet hues. It is a variety of the mineral zoisite and was discovered in 1967 in Tanzania, near Mount Kilimanjaro—its only known source in the world.

Key Characteristics of Tanzanite:

• Color: Ranges from deep blue to violet, with some stones showing a mix of both colors due to pleochroism. The most valuable tanzanites are intense, saturated blue.

• Hardness: 6 – 7 on the Mohs scale (softer than sapphire, requiring care in jewelry settings).

• Luster: Vitreous (glass-like) with excellent brilliance.

• Clarity: Usually eye-clean, though some stones may have minor inclusions.

• Refractive Index: 1.69 – 1.70, contributing to its brilliance and fire.

• Pleochroism: Displays different colors (blue, violet, and sometimes burgundy) when viewed from different angles.

• Formation: Found in metamorphic rock formations and linked to rare geological conditions that make tanzanite exceptionally scarce.

Origins and Rarity:

Tanzanite is found only in one location worldwide—the Merelani Hills of northern Tanzania. Due to its limited source and growing demand, some experts believe that tanzanite may be mined out within a few decades, increasing its long-term value.

Treatment and Enhancements:

Most tanzanites on the market undergo heat treatment to enhance their blue-violet color. This process removes brownish undertones and brings out the gemstoneâ€TMs signature hues. The treatment is permanent and widely accepted in the gem trade.

Uses and Value:

• Used in fine jewelry, especially in rings, pendants, and earrings.

• Considered the birthstone for December, along with turquoise and zircon.

• Increasingly popular as an investment gemstone due to its rarity.

Would you like a comparison between tanzanite and another gemstone, such as sapphire?