Database of luminescent Minerals

TOPAZE

Chemical Formula: Al₂SiO₄(F,OH)₂

Familly: Silicates

Status: IMA-GP

Crystal System: Orthorhombic

Mineral for Display: No

Luminescence:

Daylight Picture

TOPAZE

Photo and Copyright: Bill Barr
Used with permission of the author;

Short Waves Pictures (254nm)

TOPAZE under SWUV

Photo and Copyright: Bill Barr
Used with permission of the author;

Galerie de photos:

     To the gallery (2 images in the gallery)

Phosphorescence (in the common meaning of the term) seen by naked eye:

Thermoluminescence: Yes

Main Activator(s) and spectrum:

Most Common Activator: TiO₆

Other activators:            Cr³⁺ ,

Peaks in the spectrum (nm):

TiO₆ : broad band peaking at 455nm 

Cr³⁺ : lines at 680, 684, 695 - 697, 711, 734nm 

  To the spectrum gallery (2 spectra in the gallery)

Comments on activators and spectra:

Broad band peaking at 455 nm (TiO₆). lines at 680, 684, 695-697, 711, 734 and band peaking near 680 nm, both due to Cr³⁺

It is established by Tarashchan that all photoluminescence characteristics of variously colored topazes from Ouro Preto, Brazil are due to three structurally non-equivalent Cr3+ centers isomorphically substituting Al3+ in the topaz structure and forming [CrO₄F₂]⁷⁻, [CrO₄OH,F]⁷⁻, and [CrO₄(OH)₂]⁷⁻ complexes. (Source: Luminescence spectroscopic study of Cr3+ in Brazilian topazes from Ouro Preto by A. N. Tarashchan and Al. see below).

Laser-induced time-resolved technique enables to detect three different Cr³⁺ and possibly Mn⁴⁺ and (TiO₄) emission centers (Gaft et al. 2003a) 

Best Locality for luminescence(*):

• Shengus, Haramosh Mts., Skardu District, Gilgit-Baltistan, Pakistan (LW: yellowish or bright orange, SW: greenish white or bright yellow)
• Mine de Vermelhão, Saramenha,Ouro Preto, Minas Gerais, Brazil (very weak or laser induced red,Cr³⁺);
• Schneckenstein, former DDR, Germany (SW weak Yellow/green (De Ment));
• Boise Co., Idaho, USA (Yellow-orange);
• Zapot Topaz Mine, Zapot pegmatite, Gillis Range, Fitting District, Mineral Co., Nevada, USA (yellow LW);
• Teixerinha Mine, Itinga, Minas Gerais  Brazil (06-07/2006, zoned fluorescence SW);

(*)Data are not exhaustive and are limited to the most important localities for fluorescence

Bibliographical Reference for luminescence:

• The Henkel Glossary of Fluorescent Minerals, Dr. Gerhard Henkel, Published by the FMS, 1989 ,
• Fluorescence: Gems and Minerals Under Ultraviolet Light, Manuel Robbins, 1994, Geoscience Press, ISBN 0-945005-13-X ,
• The World of Fluorescent Minerals, Stuart Schneider, Schiffer Publishing, 2006, ISBN 0-7643-2544-2 ,
• Luminescence Spectroscopy of Minerals and Materials, M. Gaft, R. Reisfeld, G. Panczer, Springer Editor, ISBN: 10 3-540-21918-8 ,
• Handbook of Fluorescent Gems and Minerals, a practical guide for the gem and mineral collector, Jack de Ment, 1949 ,

Luminescence Reference on internet:

• Luminescence spectroscopic study of Cr3+ in Brazilian topazes from Ouro Preto by A. N. Tarashchan; M. N. Taran; H. Rager; W. Iwanuch, Physics and Chemistry of Minerals, Volume 32, Number 10 / janvier 2006 (pp. 679-690).
• Time-resolved luminescence of Cr³⁺ in topaz Al₂SiO₄(OH,F)₂, M. Gaft, L. Nagli, R. Reisfeld, G. Panczer, M. Brestel, Journal of Luminescence Volumes 102–103, May 2003, Pages 349–356
• UV-Waves September/October 1996, UV Minerals in former East Germany by H.J.Weller and J. Slacik reprinted from Fundgrube, XXVI, 1990,#3

 

Images:

 

• Shengus, Skardu District, Gilgit, Pakistan LW: https://www.mindat.org/photo-818295.html
• Shengus, Skardu District, Gilgit, Pakistan SW: https://www.mindat.org/photo-818296.html
• Shengus, Skardu District, Gilgit, Pakistan various specimens: https://www.mindat.org/photo-818797.html

Mineralogical Reference on internet:

  http://www.mindat.org/show.php?name=Topaze

  http://webmineral.com/data/Topaze.shtml

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