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This page kindly sponsored by Tanzanite Jewelry Designs & Crystals
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About TanzaniteHide

A variety of Zoisite

A gem variety of zoisite with a blue to blue-violet colour. The colour is due to the incorporation of trace amounts of vanadium cations (V4+ absorption band increased at 380 nm, V3+ absorption band at 350nm decreased with heating).

Note that a significant percentage of tanzanite crystals on the market have been heat-treated (400-500°C) to produce or enhance this colour, many are originally brown or pale grey (Hurlbut 1969; see photo to the right). A red tint seen looking down the c-axis is a good indication that the crystal colouration is natural. Note also that tanzanion is used as a synthetic simulant for tanzanite.
Natural and heat-treated tanzanite is strongly pleochroic (Hurlbut 1969). The photo to the right shows a single crystal viewed from different directions.

First reported from the Merelani Hills (Mererani), Tanzania.

Visit gemdat.org for gemological information about Tanzanite.

Pronounciation of TanzaniteHide

PlayRecorded byCountry
Jolyon & Katya RalphUnited Kingdom

Chemical Properties of TanzaniteHide


Synonyms of TanzaniteHide

Other Language Names for TanzaniteHide

Common AssociatesHide

Associated Minerals Based on Photo Data:
Graphite30 photos of Tanzanite associated with Graphite on mindat.org.
Prehnite23 photos of Tanzanite associated with Prehnite on mindat.org.
Chabazite12 photos of Tanzanite associated with Chabazite on mindat.org.
Calcite9 photos of Tanzanite associated with Calcite on mindat.org.
Quartz9 photos of Tanzanite associated with Quartz on mindat.org.
Pyrite8 photos of Tanzanite associated with Pyrite on mindat.org.
Stilbite subgroup8 photos of Tanzanite associated with Stilbite subgroup on mindat.org.
Laumontite7 photos of Tanzanite associated with Laumontite on mindat.org.
Fluorite5 photos of Tanzanite associated with Fluorite on mindat.org.
Diopside5 photos of Tanzanite associated with Diopside on mindat.org.

Other InformationHide

Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

References for TanzaniteHide

Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Hurlbut, C.S., Jr. (1969) Gem zoisite from Tanzania. American Mineralogist, 54, 702-709.
Faye and Nickel (1971): Can. Mineral., 10, 812-821.
Guebelin, E. and Weibel, M. (1976): Neuer Untersuchungen am blauen Zoisit (Tanzanit). Z. dt Gemmol. Ges., 25, 23.
Wilson, W.E., Saul, J.M. Pardieu, V. & Hughes R.W. (2009) Famous Mineral Localities. The Merelani Tanzanite Mines, Lelatema Mountains, Arusha Region, Tanzania. Mineralogical Record, 40, 347-408.
Harris, C., Hlongwane, W., Gule. N. and Scheepers, R. (2014): Origin of tanzanite and associated gemstone mineralization at Merelani, Tanzania. South African Journal of Geology, 117, 15-30.
Pimthong Thongnopkun, Phet-Anong Chanwanitsakun (2018) Color improvement using heat treatment and characteristic spectra of brownish yellow zoisite. in abstracts of the 22nd IMA Meeting Melbourne p 518.

Internet Links for TanzaniteHide

Localities for TanzaniteHide

This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.

Locality ListHide

- This locality has map coordinates listed. - This locality has estimated coordinates. ⓘ - Click for further information on this occurrence. ? - Indicates mineral may be doubtful at this locality. - Good crystals or important locality for species. - World class for species or very significant. (TL) - Type Locality for a valid mineral species. (FRL) - First Recorded Locality for everything else (eg varieties). Struck out - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (eg from pseudomorphs.)

All localities listed without proper references should be considered as questionable.
No reference listed
  • Manyara Region
    • Simanjiro District
      • Lelatema Mts
        • Merelani Hills (Mererani)
Wilson, W.E., Saul, J.M. Pardieu, V. & Hughes R.W. (2009): Famous Mineral Localities. The Merelani Tanzanite Mines, Lelatema Mountains, Arusha Region, Tanzania. Mineralogical Record, 40: 347-408.
Wilson, W.E., Saul, J.M. Pardieu, V. & Hughes R.W. (2009): Famous Mineral Localities. The Merelani Tanzanite Mines, Lelatema Mountains, Arusha Region, Tanzania. Mineralogical Record, 40: 347-408.
Min Rec (2009) 40:347-408
Olivier, Bernard (2008): The geology and petrology of the Merelani tanzanite deposit, NE Tanzania. Doctoral thesis, University of Stellenbosch, South Africa.
Andy Seibel
Natural HistoryMuseum of Los Angeles Co.specimen catalogue No. 41249.
Mineral and/or Locality  
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