The fascinating color palette of Tanzanite, which ranges from blue to brown, yellow, green, red and violet, results from the geological uniqueness of its formation. The presence of vanadium and iron in the chemical composition of Tanzanite plays a crucial role. These trace elements selectively absorb certain wavelengths of light, thereby creating the striking color spectrum of this gemstone.

Tanzanite's unique property, called pleochroism, adds another fascinating dimension to its visual appearance. From different angles or more precisely: depending on the position of the crystal axes, the tanzanite shows different colors (blue/red-violet/yellow-brown; see video below). This optical phenomenon is due to the crystal structure of the gemstone, which allows it to absorb light differently depending on the direction of its axis. Heating the crystal causes the yellow-brown color to disappear and intensifies the blue and violet. The trichroism of the unheated Tanzanite becomes dichroism. The pleochroism property makes Tanzanite a particularly multi-faceted and sought-after gemstone in the world of mineralogy.