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How to Identify Synthetic Tanzanite

Tanzanite is the gemstone quality of zoisite and is found only in Kenya and Tanzania. This blue-violet stone sits on the Mohs scale between 6 and 7 which means that it is a soft stone prone to scratch and cleave easily. Refractive index and specific gravity tests performed by trained gemologists are the only definitive way to "know" that a stone is Tanzanite. Stones marked as Tanzanite can be visually examined by close observation of the color. Synthetic Tazanite is called Tanzanion and is created to be a harder stone than real Tanzanite.

Things You'll Need

Clear daylight or lamp light
Mounted or unmounted Tanzanite

Instructions

- 1
  Stand at a window on a clear day or in front of a lamp holding the unmounted or mounted Tanzanite stones.
- 2
  Turn the stones upside down and slowly begin to examine them at 45-degree increments while holding them up to the available light.
- 3
  Note the color at each turn. Tanzanite should only return varying shades of violet and blue.
- 4
  Turn the stones upright and perform the same test. There should be no significant "grayness" to the colors viewed. A gray color identifies the stone as another type of stone or a synthetic.
- 5
  Request a refractive index and specific gravity test from a reputable gemstone dealer for definitive proof. The cost will vary from around $75 to $100 and results will be returned in several weeks.

Rocks & Minerals