Advertisement
Ad space (header)

Topaz vs Tanzanite

Topaz is harder (Mohs 8) than Tanzanite (Mohs 6–7), so it resists scratching better; Tanzanite is softer than quartz dust (7) and needs more care in everyday rings.

Tanzanite has the higher refractive index (1.691–1.700 vs 1.609–1.643), which a refractometer can use to separate them.

Topaz is denser (SG 3.53 vs 3.35); a topaz of the same size weighs about 5% more.

Advertisement
Ad space (in-content)
PropertyTopazTanzanite
Species / materialTopazZoisite
Mohs hardness86–7
Refractive index1.609–1.6431.691–1.700
Specific gravity3.533.35
Crystal systemOrthorhombicOrthorhombic
Birefringence0.008–0.0100.008–0.013

Values are typical ranges from standard gemmological references; individual stones can vary.

Test it yourself

More comparisons

Advertisement
Ad space (footer)