Database of luminescent Minerals


Chemical Formula: (Na,K)10Ca5Al6Si32O80(Cl2,F2,SO4)3 18H2O

Familly: Silicates

Status: IMA-GP

Crystal System: Orthorhombic

Mineral for Display: No


UV Type Main color Intensity Observation Frequency
Long Waves (365nm):      Orange Strong
Short Waves (254 nm):      Orange Medium

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

No Data


Named in 1959 by Th. G. Sahama and K. Hytönen after Fernand Delhaye (Clermont-Ferrand February 4 1880 - Saint-Gillis (Brussels) December 15 1946), of Belgian nationality. He worked in Central Africa (Type locality for Delhayeite: Mt Shaheru, Mt Nyiragongo, Goma, Kivu, Democratic Republic of Congo (Zaïre) type specimen conserved at Royal Museum for Central Africa, Tervuren seems not to be luminescent).

Main Activator(s) and spectrum:

Most Common Activator: S2-

Other activators:            Ce3+ , Sm3+ , Eu3+ , Dy3+ , Mn2+ , Nd3+ ,

Peaks in the spectrum (nm):

S2- : large band centered at  620nm with weak vibrational structure (564, 584, 608, 622, 645, 664, 692, 719, 747nm)

Excitation: laser 405nm. Col. G. Barmarin; Spectre: G. Barmarin


  To the spectrum gallery (3 spectra in the gallery)

Comments on activators and spectra:

Delhayelite was studied by steady-state luminescence and S2- , trivalent REE, such as Ce, Dy, Sm, and Mn2+ were found.


Excitation by CW laser at 532 and 785 nm revealed trivalent REE, mainly Eu and Nd, and evidently S2-  band (Gaft).

Best Locality for luminescence(*):

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

Bibliographical Reference for luminescence:

Luminescence Reference on internet:

Mineralogical Reference on internet:

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