1 pcs Blue Tanzanite - 15.89 ct - Antwerp Laboratory for Gemstone Testing (ALGT)

Tanzanite is a striking blue-violet gemstone unique to Tanzania, known for its rare and vibrant color that can appear different depending on lighting conditions, a phenomenon called pleochroism. This sizeable 15.89 carat blue tanzanite is an impressive specimen highlighting the gem's exceptional saturation and brilliance. Formed by the alteration of the mineral zoisite under specific geological conditions, tanzanite has become a popular alternative to sapphires in fine jewelry since its relatively recent discovery in the 1960s. The Antwerp Laboratory for Gemstone Testing (ALGT) certifies this gem, ensuring its authenticity and confirming its characteristics, an essential factor given the prevalence of enhancements such as heat treatment commonly applied to tanzanite to improve color.