Database of luminescent Minerals

SPODUMENE

Chemical Formula: LiAlSi₂O₆

Familly: Silicates

Status:

Crystal System: Monoclinic

Mineral for Display: Yes

Luminescence:

Long Waves Picture (365nm)

OL (365 nm). Col. G. Barmarin; Photo: G. Barmarin

Galerie de photos:

     To the gallery (7 images in the gallery)

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

Ténébrescence: OUI

Thermoluminescence: Yes

Comments:

Variety triphane (colorless), Kunzite (pink) and Hiddenite (green).

Main Activator(s) and spectrum:

Most Common Activator: Mn²⁺

Other activators:            Cr³⁺ , Fe³⁺ ,

Peaks in the spectrum (nm):

Mn²⁺ substituting for Li : broad band around 595 - 615nm (10ms)

Cr³⁺ : 676, 690nm (peak)

Fe³⁺ : 685nm (5 ms)

Comments on activators and spectra:

Mn²⁺ is shown to be mainly in Li-sites rather than Al-sites and gives rise to a broad emission centered at 600 nm. In Cr-rich crystals only one R1 line is observed and Cr³⁺ emission is evident at room temperature. In green hiddenite crystals, Cr³⁺ emission is dominant at room temperature where the R-lines are superimposed on a broad-band emission. (Source: Luminescence spectroscopy of Cr³⁺ and Mn²⁺ in spodumene (LiAlSi₂O₆), WALKER G. see below).

Spodumen is a monoclinic pyroxene with two not equivalent metal cation sites M1 and M2. The aluminum occupies the smaller M1 site, which is approximately octahedral (actual symmetry C2) with an average metal-oxygen distance of 1.92 A. The M2 site, occupied by Li, is also six-fold coordinated with an average metal-oxygen distance of 2.23 Å. Both Al and Li sites may be substitutionally replaced by ions of the transitional metals in various proportions.

Both Mn²⁺ and Cr³⁺ centers have been identified in luminescence spectra by steadystate spectroscopy (Tarashchan 1978; Walker et al. 1997).

Besides, long lived deep red luminescence was found supposedly generated by Fe³⁺ especially in the specimen fluorescing a bright lilac color under SW, light peach LW and having a violet (not pink) color in daylight.

At room and lower temperatures only one emission band of Mn2+ occurs. 

It is very probable that Mn²⁺ ions in the spodumen matrix is present only in one site and that Mn²⁺ is mainly in Li-sites rather than Al-sites. (Gaft)

Best Locality for luminescence(*):

• Hunza Mine, Gilgit Region, Pakistan;
• Kolum District, Nuristan Region, Afghanistan;
• Kunar Province, Afghanistan;
• Laghman Province, Afghanistan;
• Dara-i-Pech pegmatite field, Chapa Dara District, Konar Province, Afghanistan (orange LW,lilac SW+phosphp);
• Minas Gerais, Brazil;
• Pala Chief Mine, Chief Mountain, Pala, Pala District, San Diego Co., California, USA (dull luminescence);
• Strickland Quarry, Strickland pegmatite, Collins Hill, Portland, Middlesex Co., Connecticut, USA (pink LW, Blue SW);
• Stony Point, Alexander Co., North Carolina, USA (strong LW, dull SW);
• Oceanview Mine, Elizabeth R. Mine, Chief Mountain, Pala, Pala District, San Diego Co., California, USA ( intense UV fluorescence as well as phosphorescence);

(*)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 ,

Luminescence Reference on internet:

• Composition, tenebrescence and luminescence of spodumene minerals, Esther W. Claffy, American Mineralogist vol38
• Luminescence spectroscopy of Cr3+ and Mn2+ in spodumene (LiAlSi2O6), Walker G., El Jaer A., Sherlock R., Glynn T. J., Czaja M., Mazurak Z., Journal of luminescence, 1997, vol. 72-74, pp. 278-280

 

Images:

 

• Minas Gerais, Brazil: http://www.mindat.org/photo-87001.html
• Strickland Quarry LW, USA: http://www.mindat.org/photo-337838.html
• Strickland Quarry SW, USA: http://www.mindat.org/photo-337839.html
• Laghman Province, Afghanistan: http://www.mindat.org/photo-613704.html
• Laghman Province, Afghanistan : https://www.mindat.org/photo-525454.html
• Dara-i-Pech pegmatite field, Afghanistan: http://www.mindat.org/photo-665586.html
• Kunar, Afghanistan (including phosphorescence): https://www.mindat.org/photo-754998.html

Mineralogical Reference on internet:

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

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

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