Database of luminescent Minerals

LAZURITE

Chemical Formula: Na₆Ca₂Al₆Si₆O₂₄[(SO₄),S,Cl,(OH)]₂

Familly: Silicates

Status: IMA-GP

Crystal System: Isometric

Mineral for Display: No

Luminescence:

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

Thermoluminescence: Yes

Comments:

This is a mineral of the sodalite family, more precisely a sulfide rich variety of Hauyne.

Lazurite is the blue component of the Lapis Lazuli, which is a Lazurite-Calcite-Pyrite rock.

From Lyadjvar, Pamir mountains, Tadjikistan. Fluoresces bluish under LW.

Lazurite of Ovalle Chile said to be thermoluminescente and phosphorescente by De Ment (associated calcite?) (see bibliography)

Main Activator(s) and spectrum:

Most Common Activator: S₂^-

Other activators:            Fe³⁺ , Mn²⁺ , Nd³⁺ ,

Comments on activators and spectra:

Emission of S₂^- centers with vibrational structure even at room temperature was identified by Tarashchan (1978).

In his study of S₂^- Gaft revealed that this center has very fast decay of approximately 200–500 ns enabling to quench it by relatively small delay time and to detect other previously hidden luminescence centers. This approach revealed, besides S₂^- emission two broad bands not definitely identified yet, but the last one evidently belongs to Mn²⁺ based on its spectral position and form and long decay time. Excitation by CW laser at 532 and 780 nm revealed evidently luminescence of Nd³⁺, Fe³⁺, Mn²⁺ (broad band at 575nm) and S₂^- (broad band  at 620nm with weak vibrational structure) centers.

Best Locality for luminescence(*):

• Lyadjvar, Pamir Mountains, Tadjikistan (bluish LW);
• Ladjuar Medam, Sar-e Sang, Koksha Valley, Khash & Kuran Wa Munjan Districts, Badakhshan Province, Afghanistan;
• Tultui lazurite deposit, Malaya Bystraya River Valley, Slyudyanka, Lake Baikal area, Irkutsk Oblast, Russia (red 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 ,
• Luminescent Spectra of Minerals, Boris S. Gorobets and Alexandre A. Rogojine, Moscow, 2002 ,
• Handbook of Fluorescent Gems and Minerals, a practical guide for the gem and mineral collector, Jack de Ment, 1949 ,

Mineralogical Reference on internet:

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

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

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