Tanzanite from Tanzania - Double Terminated

A Tanzanite double-terminator from the Merelani Hills, Tanzania, with pyramid terminations on both sides. The deep blue color intensity and the clarity of the column's center make this piece a select collector's specimen from this unique deposit.

Tanzanite is the blue to violet variety of zoisite, a calcium aluminum hydroxysilicate. The coloration comes from trace amounts of vanadium in the crystal lattice; the pleochroism, i.e., the color shimmer depending on the viewing angle, is diagnostic and very pronounced on this double terminator.

Double-terminated crystals with points crystallized on both sides are a rarity for tanzanite within an already rare deposit. Most tanzanites are single-terminated or have been cleaved after recovery. A free-standing, double-terminated specimen documents the undisturbed cavity genesis in the pegmatite veins.

The Merelani Hills are the only known deposit for tanzanite, located in northern Tanzania at the foot of Kilimanjaro. Geological estimates suggest the deposit will be exhausted in two to three decades, which continuously increases its collector's value.

A gemologically noteworthy collector's item with a clear geological and historical context.