Tanzanite is the violet-blue to blue-violet variety of the mineral zoisite. Zoisite itself naturally occurs in a wide range of colors, including gray, yellow, brown, green, colorless, blue, and violet. Tanzanite is unique because of its striking blue shades, which make it highly sought after as a gemstone. Its captivating color is due to the presence of the element vanadium. This rare gemstone has quickly become a favorite among collectors and jewelry lovers alike.