Delhayelite
A valid IMA mineral species
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About Delhayelite
Formula:
(Na,K)10Ca5Al6Si32O80(Cl2,F2,SO4)3 · 18H2O
Colour:
Colourless; Silver-grey, Greenish-grey
Specific Gravity:
2.60
Crystal System:
Orthorhombic
Member of:
Name:
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.
Easily hydrothermally altered to hydrodelhayelite. Chemically somewhat similar to steudelite and sacrofanite.
Unique Identifiers
Mindat ID:
1251
Long-form identifier:
mindat:1:1:1251:1
GUID
(UUID V4):
(UUID V4):
e3f09ba8-3a5f-43b7-b239-164a59e0041e
IMA Classification of Delhayelite
Approved
IMA Formula:
K7Na3Ca5Al2Si14O38F4Cl2
First published:
1959
Classification of Delhayelite
9.EB.10
9 : SILICATES (Germanates)
E : Phyllosilicates
B : Double nets with 4- and 6-membered rings
9 : SILICATES (Germanates)
E : Phyllosilicates
B : Double nets with 4- and 6-membered rings
72.5.1.4
72 : PHYLLOSILICATES Two-Dimensional Infinite Sheets with Other Than Six-Membered Rings
5 : Two-Dimensional Infinite Sheets with Other Than Six-Membered Rings with corrugated and complex layers
72 : PHYLLOSILICATES Two-Dimensional Infinite Sheets with Other Than Six-Membered Rings
5 : Two-Dimensional Infinite Sheets with Other Than Six-Membered Rings with corrugated and complex layers
17.10.9
17 : Silicates Containing other Anions
10 : Silicates with sulphate, molybdate or tungstate
17 : Silicates Containing other Anions
10 : Silicates with sulphate, molybdate or tungstate
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
Symbol | Source | Reference |
---|---|---|
Dhy | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Delhayelite
Transparency:
Translucent
Colour:
Colourless; Silver-grey, Greenish-grey
Cleavage:
Distinct/Good
Parallel to (010)
Parallel to (010)
Density:
2.60(3) g/cm3 (Measured) 2.50 g/cm3 (Calculated)
Optical Data of Delhayelite
Type:
Biaxial (-)
RI values:
nα = 1.530 - 1.532 nβ = 1.532(2) nγ = 1.533 - 1.533
2V:
Measured: 83° (3), Calculated: 83°
Birefringence:
observed birefringence is 0.002-0.003; reported α, β, and γ all given as ≈1.532; the calculated birefringence from having these values all assigned as 1.532 yields δ=0.000, which is not quite correct. Hence, α and γ were slightly adjusted (3rd and 4th decimal place, still within measured errors) to give the correct birefringence and measured 2V°.
Max Birefringence:
δ = 0.003
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:
Low
Dispersion:
weak
Pleochroism:
Non-pleochroic
Comments:
nominally colorless, but sections cut perpendicular to [010] may show an anomalous bluish-gray color.
Comments:
X=a, Y=c, Z=b
Chemistry of Delhayelite
Mindat Formula:
(Na,K)10Ca5Al6Si32O80(Cl2,F2,SO4)3 · 18H2O
Common Impurities:
Ti,Fe,Mn,Mg
Crystallography of Delhayelite
Crystal System:
Orthorhombic
Cell Parameters:
a = 13.06 Å, b = 24.65 Å, c = 7.04 Å
Ratio:
a:b:c = 0.53 : 1 : 0.286
Unit Cell V:
2,266.38 ų (Calculated from Unit Cell)
Z:
1
Morphology:
platy
Comment:
Point Group: 2/m 2/m 2/m or mm2; Space Group: Pmmn or Pmn21
Crystal Structure
Load
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Show
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
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Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
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Perspective On | Perspective Off
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2D | Stereo | Red-Blue | Red-Cyan
View
CIF File Best | x | y | z | a | b | c
CIF File Best | x | y | z | a | b | c
Rotation
Stop | Start
Stop | Start
Labels
Console Off | On | Grey | Yellow
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Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
---|---|---|---|---|---|---|---|
0015364 | Delhayelite | Cannillo E, Rossi G, Ungaretti L (1970) The crystal structure of delhayelite Rendiconti della Societa Italiana di Mineralogia e Petrologia 26 63-75 | 1970 | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
3.078 Å | (100) |
12.3 Å | (35) |
6.158 Å | (25) |
3.482 Å | (10) |
2.961 Å | (5) |
2.788 Å | (5) |
1.760 Å | (5) |
Geological Environment
Paragenetic Mode(s):
Paragenetic Mode | Earliest Age (Ga) |
---|---|
Stage 4b: Highly evolved igneous rocks | >3.0 |
35 : Ultra-alkali and agpaitic igneous rocks |
Type Occurrence of Delhayelite
Place of Conservation of Type Material:
Royal Museum for Central Africa, Tervuren, Belgium, RGM8037.
Associated Minerals at Type Locality:
Reference:
Sahama, T.G., Hytönen, K. (1959) Delhayelite, a new silicate from the Belgian Congo. Mineralogical Magazine: 32: 6-9.
Other Language Names for Delhayelite
German:Delhayelit
Spanish:Delhayelita
Relationship of Delhayelite to other Species
Member of:
Other Members of this group:
Fivegite | K4Ca2[AlSi7O17(O2-xOHx)][(H2O)2-xOHx]Cl | Orth. mm2 : Pmn21 |
Hydrodelhayelite | KCa2AlSi7O17(OH)2 · 6H2O | Orth. mm2 |
Melansonite | Na◻KZrSi8O19 · 5H2O | Orth. mmm (2/m 2/m 2/m) : Pmma |
Monteregianite-(Y) | (Na,K)6(Y,Ca)2Si16O38 · 10H2O | Mon. 2/m |
Natromelansonite | Na3Zr[Si7AlO19] · 4H2O | Mon. 2/m : P21/m |
Rhodesite | KHCa2Si8O19 · 5H2O | Orth. mmm (2/m 2/m 2/m) |
Common Associates
Associated Minerals Based on Photo Data:
9 photos of Delhayelite associated with Aegirine | NaFe3+Si2O6 |
3 photos of Delhayelite associated with Fenaksite | (K,Na)4(Fe,Mn)2(Si4O10)2(OH,F) |
3 photos of Delhayelite associated with Hisingerite | Fe3+2(Si2O5)(OH)4 · 2H2O |
2 photos of Delhayelite associated with Microcline | K(AlSi3O8) |
1 photo of Delhayelite associated with Canasite | K3Na3Ca5Si12O30(OH)4 |
1 photo of Delhayelite associated with Titanite | CaTi(SiO4)O |
1 photo of Delhayelite associated with Fivegite | K4Ca2[AlSi7O17(O2-xOHx)][(H2O)2-xOHx]Cl |
1 photo of Delhayelite associated with Zircon | Zr(SiO4) |
1 photo of Delhayelite associated with Villiaumite | NaF |
1 photo of Delhayelite associated with Lamprophyllite | (Na,Mn2+)3(Sr,Na)2(Ti,Fe3+)3(Si2O7)2O2(OH,O,F)2 |
Related Minerals - Strunz-mindat Grouping
9.EB. | Natromelansonite | Na3Zr[Si7AlO19] · 4H2O |
9.EB.05 | Macdonaldite | BaCa4Si16O36(OH)2 · 10H2O |
9.EB.05 | Rhodesite | KHCa2Si8O19 · 5H2O |
9.EB.05 | Melansonite | Na◻KZrSi8O19 · 5H2O |
9.EB.10 | Hydrodelhayelite | KCa2AlSi7O17(OH)2 · 6H2O |
9.EB.15 | Monteregianite-(Y) | (Na,K)6(Y,Ca)2Si16O38 · 10H2O |
9.EB.20 | Carletonite | KNa4Ca4Si8O18(CO3)4(OH,F) · H2O |
9.EB.20 | Fluorcarletonite | KNa4Ca4Si8O18(CO3)4F · H2O |
9.EB.25 | Günterblassite | (K,Ca,Ba)2(Fe,Ca,Mg,Na)[(Si,Al)13O25(OH)4] · 7H2O · |
9.EB.25 | Umbrianite | K7Na2Ca2[Al3Si10O29]F2Cl2 |
9.EB.25 | Hillesheimite | (K,Ca,Ba,◻)2(Mg,Fe,Ca,◻)2[(Si,Al )13O23(OH)6](OH) · 8H2O |
9.EB.30 | Fivegite | K4Ca2[AlSi7O17(O2-xOHx)][(H2O)2-xOHx]Cl |
Fluorescence of Delhayelite
Orange (from Khibiny, Russia)
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.
Internet Links for Delhayelite
mindat.org URL:
https://www.mindat.org/min-1251.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Delhayelite
Reference List:
Localities for Delhayelite
Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for references and further information on this occurrence.
? - Indicates mineral may be doubtful at this locality.
- Good crystals or important locality for species.
- World class for species or very significant.
(TL) - Type Locality for a valid mineral species.
(FRL) - First Recorded Locality for everything else (eg varieties).
Struck out - Mineral was erroneously reported from this locality.
Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).
All localities listed without proper references should be considered as questionable.
All localities listed without proper references should be considered as questionable.
DR Congo | |
| Richard +15 other references |
| Mineralogical Magazine (1959) |
Italy | |
| Sabatini (1899) +8 other references |
Morocco | |
Berger et al. (2009) | |
Russia | |
| Pekov (1998) |
Yakovenchuk et al. (2005) | |
[World of Stones 95:5-6 | |
Pekov (1998) | |
Arzamastsev et al. (2008) +1 other reference | |
Pekov (1998) +1 other reference | |
| Pavel Kartashov specimens. +3 other references |
Pekov (1998) | |
Khomyakov et al. (1983) +1 other reference | |
Tanzania | |
| Dawson (1998) |
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Kirovskii apatite mine, Kukisvumchorr Mt, Khibiny Massif, Murmansk Oblast, Russia