Tanzanite is a rare and captivating gemstone known for its rich blue-to-violet colour and remarkable optical effects. Here’s a clear, practical breakdown:

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What is Tanzanite?

• A variety of zoisite (a calcium aluminium silicate mineral)

• Discovered in 1967 in northern Tanzania, near Mount Kilimanjaro

• Found in only one place on Earth, making it exceptionally rare

 

Colour & Appearance

• Famous for its deep blue, violet, and purplish hues

• Often shows pleochroism — meaning it displays different colours from different angles (blue, violet, sometimes burgundy)

 

Physical Properties

• Hardness: 6–7 on the Mohs scale (softer than sapphire or diamond)

• Clarity: Typically eye-clean in higher grades

• Cut: Often faceted to maximise colour shifts and brilliance

 

Value Factors

Tanzanite pricing depends on:

• Colour intensity (deep, saturated blue-violet is most valuable)

• Clarity

• Carat size (larger stones increase significantly in value)

• Cut quality

 

Durability & Care

• More delicate than many gemstones → can scratch or chip

• Avoid:

  • Hard knocks

  • Ultrasonic cleaners

• Best suited for earrings, pendants, or occasional-wear rings

 

Why It’s Special

• 1,000 times rarer than diamonds (by some estimates)

• Single-source gemstone → supply is finite

• Marketed as a modern alternative to sapphire with unique colour play

 

Fun Fact

Tanzanite is a December birthstone, alongside turquoise and zircon.

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