Tanzanite

Carat weight is a major driver of value. Fine tanzanite in larger sizes (5–10 carats and above) with strong color and good clarity is significantly more valuable per carat than smaller stones. Stones over 20 carats in top quality are rare and command strong premiums.

Color is the primary value factor. The finest tanzanite displays a saturated, vivid violetish-blue to bluish-violet with good balance between blue and purple components, remaining lively in a range of lighting. Pale stones or those with a strong brownish cast are less valuable. Heat treatment is commonly used to remove brownish tones and enhance blue-violet color.

Tanzanite is often eye-clean in faceted gems, and buyers expect good clarity. Obvious inclusions or fractures that break the surface lower both beauty and durability. Fine, clean stones with strong color are especially prized, particularly in larger sizes.

Cutting tanzanite requires balancing pleochroism, color and weight retention. Well-cut stones show a rich, even face-up color and good brilliance without excessive extinction. Because of cleavage, cutters must orient stones carefully and avoid designs that leave thin, vulnerable areas. Ovals, cushions and emerald cuts are common.

Tanzanite is found almost exclusively in a small mining area near Mererani in northern Tanzania, making it a geographically restricted gemstone. Production is variable and influenced by mining conditions, regulatory changes and local infrastructure.

Demand for tanzanite is strong, particularly in North America and Europe, where it is marketed as an exotic, modern alternative to sapphire. It is widely used in mid- to high-end jewelry, often as large center stones with diamond accents.

Recent Trends: generally robust demand, with periodic price fluctuations linked to changes in mine output and marketing efforts.