Tanzanite jewelry is typically a bluish-purple color, the color of the tanzanite gemstone. Some tanzanite is more on the blue side, while other tanzanite has hints of violet in it.
Tanzanite is simply a trade name for the mineral zoisite. Zoisite comes in many different colors, such as blue, purple, pink, gray, yellow, brown and green. When the mineral is a bluish or bluish-purple color, it is considered tanzanite. Some of the bluish tones of tanzanite are from zoisite having small amounts of vanadium inside it.
When it is heated, it turns into the classic bluish-violet radiant. Jewelry metal can change the look of tanzanite slightly, such as a slightly different hue with yellow gold jewelry as opposed to white gold.