Eylettersite
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About Eylettersite
Formula:
Th0.75Al3(PO4)2(OH)6
The type material contains minor Pb replacing Th, and minor Si replacing P.
Colour:
Cream white
Lustre:
Vitreous
Hardness:
3 - 4
Crystal System:
Trigonal
Member of:
Name:
Named in 1972 by L. Van Wambeke after his wife, Lea Eyletters.
Type Locality:
This page provides mineralogical data about Eylettersite.
Classification of Eylettersite
Approved
First Published:
1972
7/B.36-100
8.BL.10
8 : PHOSPHATES, ARSENATES, VANADATES
B : Phosphates, etc., with additional anions, without H2O
L : With medium-sized and large cations, (OH, etc.):RO4 = 3:1
8 : PHOSPHATES, ARSENATES, VANADATES
B : Phosphates, etc., with additional anions, without H2O
L : With medium-sized and large cations, (OH, etc.):RO4 = 3:1
41.5.12.2
41 : ANHYDROUS PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
5 : (AB)2(XO4)Zq
41 : ANHYDROUS PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
5 : (AB)2(XO4)Zq
17.6.17
17 : Silicates Containing other Anions
6 : Silicates with phosphate
17 : Silicates Containing other Anions
6 : Silicates with phosphate
Physical Properties of Eylettersite
Optical Data of Eylettersite
Type:
Uniaxial (-)
RI values:
nε = 1.615 - 1.660
Max Birefringence:
δ = 0.000

Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
and does not take into account mineral colouration.
Surface Relief:
Moderate
Chemical Properties of Eylettersite
Formula:
Th0.75Al3(PO4)2(OH)6
The type material contains minor Pb replacing Th, and minor Si replacing P.
The type material contains minor Pb replacing Th, and minor Si replacing P.
IMA Formula:
Th0.75Al3(PO4)2(OH)6
Crystallography of Eylettersite
Crystal System:
Trigonal
Cell Parameters:
a = 6.99 Å, c = 16.7 Å
Ratio:
a:c = 1 : 2.389
Unit Cell V:
706.65 ų (Calculated from Unit Cell)
Type Occurrence of Eylettersite
Place of Conservation of Type Material:
Euratom, Ispra, Italy
Reference:
van Wambeke, L. (1972) Eylettersite, un nouveau phosphate de thorium appartenant à la série de la crandallite. Bulletin de la Société Française de Minéralogie et de Cristallographie: 95: 98-105.
Synonyms of Eylettersite
Other Language Names for Eylettersite
German:Eylettersit
Spanish:Eylettersita
Relationship of Eylettersite to other Species
Member of:
Other Members of this group:
Benauite | SrFe3+3(HPO4,PO4)2(OH)6 | Trig. 3m (3 2/m) : R3m |
Crandallite | CaAl3(PO4)(PO3OH)(OH)6 | Trig. 3m (3 2/m) : R3m |
Florencite-(Ce) | CeAl3(PO4)2(OH)6 | |
Florencite-(La) | LaAl3(PO4)2(OH)6 | |
Florencite-(Nd) | NdAl3(PO4)2(OH)6 | |
Florencite-(Sm) | SmAl3(PO4)2(OH)6 | Trig. 3m (3 2/m) : R3m |
Galloplumbogummite | Pb(Ga,Al,Ge)3(PO4)2(OH)6 | Trig. 3m : R3m |
Gorceixite | BaAl3(PO4)(PO3OH)(OH)6 | Mon. m : Bm |
Goyazite | SrAl3(PO4)(PO3OH)(OH)6 | Trig. 3m (3 2/m) : R3m |
Kintoreite | PbFe3(PO4)(PO3OH)(OH)6 | Trig. 3m (3 2/m) : R3m |
Kintoreite-2c | PbFe3+3(PO4)2(OH,H2O)6 | |
Plumbogummite | PbAl3(PO4)(PO3OH)(OH)6 | Trig. 3m (3 2/m) : R3m |
Springcreekite | BaV3+3(PO4)2(OH,H2O)6 | Trig. 3m (3 2/m) : R3m |
Unnamed (As-analogue of Zaïrite) | (Bi,Pb)Fe3+3(AsO4)2(OH)6 | |
Waylandite | BiAl3(PO4)2(OH)6 | Trig. 3m (3 2/m) : R3m |
Zaïrite | BiFe3+3(PO4)2(OH)6 | Trig. 3m (3 2/m) : R3m |
Related Minerals - Nickel-Strunz Grouping
8.BL.05 | Beudantite | PbFe3(AsO4)(SO4)(OH)6 | Trig. 3m (3 2/m) : R3m |
8.BL.05 | Corkite | PbFe3(PO4)(SO4)(OH)6 | Trig. 3m (3 2/m) : R3m |
8.BL.05 | Hidalgoite | PbAl3(AsO4)(SO4)(OH)6 | Trig. |
8.BL.05 | Hinsdalite | PbAl3(PO4)(SO4)(OH)6 | Trig. 3m (3 2/m) : R3m |
8.BL.05 | Kemmlitzite | SrAl3(AsO4)(SO4)(OH)6 | Trig. |
8.BL.05 | Svanbergite | SrAl3(PO4)(SO4)(OH)6 | Trig. 3m (3 2/m) : R3m |
8.BL.05 | Woodhouseite | CaAl3(PO4)(SO4)(OH)6 | Trig. 3m (3 2/m) : R3m |
8.BL.05 | Gallobeudantite | PbGa3(AsO4)(SO4)(OH)6 | Trig. |
8.BL.10 | Arsenogoyazite | SrAl3(AsO4)(AsO3OH)(OH)6 | Trig. 3m (3 2/m) : R3m |
8.BL.10 | Arsenogorceixite | BaAl3(AsO4)(AsO3OH)(OH)6 | Trig. 3m (3 2/m) : R3m |
8.BL.10 | Arsenocrandallite | CaAl3(AsO4)(AsO3OH)(OH)6 | Trig. 3m (3 2/m) |
8.BL.10 | Benauite | SrFe3+3(HPO4,PO4)2(OH)6 | Trig. 3m (3 2/m) : R3m |
8.BL.10 | Crandallite | CaAl3(PO4)(PO3OH)(OH)6 | Trig. 3m (3 2/m) : R3m |
8.BL.10 | Dussertite | BaFe3+3(AsO4)(AsO3OH)(OH)6 | Trig. 3m (3 2/m) : R3m |
8.BL.10 | Gorceixite | BaAl3(PO4)(PO3OH)(OH)6 | Mon. m : Bm |
8.BL.10 | Goyazite | SrAl3(PO4)(PO3OH)(OH)6 | Trig. 3m (3 2/m) : R3m |
8.BL.10 | Kintoreite | PbFe3(PO4)(PO3OH)(OH)6 | Trig. 3m (3 2/m) : R3m |
8.BL.10 | Philipsbornite | PbAl3(AsO4)(AsO3OH)(OH)6 | Trig. |
8.BL.10 | Plumbogummite | PbAl3(PO4)(PO3OH)(OH)6 | Trig. 3m (3 2/m) : R3m |
8.BL.10 | Segnitite | PbFe3+3AsO4(AsO3OH)(OH)6 | Trig. 3m (3 2/m) : R3m |
8.BL.10 | Springcreekite | BaV3+3(PO4)2(OH,H2O)6 | Trig. 3m (3 2/m) : R3m |
8.BL.13 | Arsenoflorencite-(La) | LaAl3(AsO4)2(OH)6 | Trig. 3m (3 2/m) : R3m |
8.BL.13 | Arsenoflorencite-(Nd) | NdAl3(AsO4)2(OH)6 | Trig. |
8.BL.13 | Arsenoflorencite-(Ce) | CeAl3(AsO4)2(OH)6 | Trig. 3m (3 2/m) : R3m |
8.BL.13 | Florencite-(Ce) | CeAl3(PO4)2(OH)6 | |
8.BL.13 | Florencite-(La) | LaAl3(PO4)2(OH)6 | |
8.BL.13 | Florencite-(Nd) | NdAl3(PO4)2(OH)6 | |
8.BL.13 | Waylandite | BiAl3(PO4)2(OH)6 | Trig. 3m (3 2/m) : R3m |
8.BL.13 | Zaïrite | BiFe3+3(PO4)2(OH)6 | Trig. 3m (3 2/m) : R3m |
8.BL.13 | Arsenowaylandite | BiAl3(AsO4)2(OH)6 | Trig. |
8.BL.13 | Graulichite-(Ce) | CeFe3+3(AsO4)2(OH)6 | Trig. 3m (3 2/m) : R3m |
8.BL.13 | Florencite-(Sm) | SmAl3(PO4)2(OH)6 | Trig. 3m (3 2/m) : R3m |
8.BL.15 | Viitaniemiite | Na(Ca,Mn2+)Al(PO4)(F,OH)3 | Mon. |
8.BL.25 | Pattersonite | PbFe3+3(PO4)2(OH)5 · H2O | Tric. 1 : P1 |
Related Minerals - Dana Grouping (8th Ed.)
41.5.12.1 | Waylandite | BiAl3(PO4)2(OH)6 | Trig. 3m (3 2/m) : R3m |
41.5.12.3 | Zaïrite | BiFe3+3(PO4)2(OH)6 | Trig. 3m (3 2/m) : R3m |
Related Minerals - Hey's Chemical Index of Minerals Grouping
17.6.1 | Nagelschmidtite | Ca7(SiO4)2(PO4)2 | Hex. 6 : P61 |
17.6.2 | Perhamite | Ca3Al7.7Si3P4O23.5(OH)14.1 · 8H2O | Trig. 3m (3 2/m) : P3m1 |
17.6.3 | Viséite | ||
17.6.4 | Phosinaite | Na13Ca2(Ce,La,Th,Nd,Pr)(Si4O12)(PO4)4 | |
17.6.5 | Clinophosinaite | Na12(Ca,Sr)4(Si4O12)(PO4)4 | Mon. |
17.6.6 | Karnasurtite-(Ce) | (Ce,La,Th)(Ti,Nb)(Al,Fe)(Si2O7)(OH)4 · 3H2O | |
17.6.7 | Lomonosovite | Na5Ti2(Si2O7)(PO4)O2 | Tric. |
17.6.8 | Bornemanite | Na6BaTi2Nb(Si2O7)2(PO4)O2(OH)F | Tric. 1 : P1 |
17.6.9 | Sobolevite | Na13Ca2Mn2Ti3(Si2O7)2(PO4)4O3F3 | Mon. m : Pb |
17.6.10 | Laplandite-(Ce) | Na4CeTiPO4Si7O18 · 5H2O | |
17.6.11 | Vunonnemite | Na5TiNb3Si6O25F2 · 2Na3PO4 | |
17.6.12 | Saryarkite-(Y) | Ca(Y,Th)Al5(SiO4)2(PO4,SO4)2(OH)7 · 6H2O | Tet. 4 2 2 |
17.6.13 | Steenstrupine-(Ce) | Na14Mn2+2(Fe3+,Mn3+)2Ce6(Zr,Th)(Si6O18)2(PO4)6(HPO4)(OH)2 · 2H2O | Trig. |
17.6.14 | Waylandite | BiAl3(PO4)2(OH)6 | Trig. 3m (3 2/m) : R3m |
17.6.15 | Britholite-(Ce) | (Ce,Ca)5(SiO4)3OH | Hex. 6/m : P63/m |
17.6.16 | Britholite-(Y) | (Y,Ca)5(SiO4)3OH | Hex. 6/m : P63/m |
Other Information
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 Eylettersite
Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
van Wambeke, L. (1971) The problem of cation deficiencies in some phosphates due to alteration processes. American Mineralogist: 56: 1366-1384.
van Wambeke, L. (1972) Eylettersite, un nouveau phosphate de thorium appartenant à la série de la crandallite. Bulletin de la Société Française de Minéralogie et de Cristallographie: 95: 98-105.
Fleischer, M. (1974) New mineral names. American Mineralogist: 59: 208-212.
Jambor, J.L. (1999) Nomenclature of the alunite supergroup. The Canadian Mineralogist: 37: 1323-1341.
Bayliss, P., Kolitsch, U., Nickel, E.H., Pring, A. (2010) Alunite supergroup: recommended nomenclature. Mineralogical Magazine: 74: 919-927.
Internet Links for Eylettersite
mindat.org URL:
https://www.mindat.org/min-1430.html
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Please feel free to link to this page.
External Links:
Mineral Dealers:
Localities for Eylettersite
Locality List




All localities listed without proper references should be considered as questionable.
DR Congo (TL) | |
| Bull. Soc. fr. Minéral. (1972) 95, 98–105; HB4 (2000) |
Namibia | |
| E. Schnaitmann, F. Brandstätter, U. Kolitsch and G. Niedermayr (2008): Die „Gitterquarz“-Paragenese aus dem Erongo, Namibia. Mineralien-Welt 20 (1), 55-63. |
Kobokobo pegmatite, Mwenga, Sud-Kivu, DR Congo