Englishite
A valid IMA mineral species - grandfathered
This page is currently not sponsored. Click here to sponsor this page.
About Englishite
George L. English
Formula:
K3Na2Ca10Al15(PO4)21(OH)7 · 26H2O
Colour:
Colourless to white, grayish green; colourless in transmitted light.
Lustre:
Vitreous, Pearly
Hardness:
3
Specific Gravity:
2.65 - 2.68
Crystal System:
Monoclinic
Name:
After George Letchworth English (14 June 1864, Philadelphia, Pennsylvania, USA - 2 January 1944, Winter Park, Florida, USA), mineral collector and dealer, New York, New York, USA. A study of his collection of phosphate nodules led to the discovery of several minerals including this one.
This page provides mineralogical data about Englishite.
Unique Identifiers
Mindat ID:
1383
Long-form identifier:
mindat:1:1:1383:9
IMA Classification of Englishite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
K3Na2Ca10Al15(OH)7(PO4)21 · 26H2O
First published:
1930
Classification of Englishite
8.DH.55
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
H : With large and medium-sized cations, (OH, etc.):RO4 < 1:1
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
H : With large and medium-sized cations, (OH, etc.):RO4 < 1:1
42.13.8.1
42 : HYDRATED PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
13 : Miscellaneous
42 : HYDRATED PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
13 : Miscellaneous
19.8.21
19 : Phosphates
8 : Phosphates of Al and other metals
19 : Phosphates
8 : Phosphates of Al and other metals
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 |
|---|---|---|
| Egs | 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 Englishite
Vitreous, Pearly
Transparency:
Transparent
Comment:
Lustre pearly on cleavages.
Colour:
Colourless to white, grayish green; colourless in transmitted light.
Streak:
White
Hardness:
3 on Mohs scale
Tenacity:
Flexible
Cleavage:
Perfect
On {001}, perfect, micaceous.
On {001}, perfect, micaceous.
Density:
2.65 - 2.68 g/cm3 (Measured) 2.69 g/cm3 (Calculated)
Optical Data of Englishite
Type:
Biaxial (-)
RI values:
nα = 1.570 nβ = 1.572 nγ = 1.573
Max. Birefringence:
δ = 0.003
Based on recorded range of RI values above.
Based on recorded range of RI values above.
Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars.
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars.
Surface Relief:
Moderate
Dispersion:
r > v
Optical Extinction:
X = c; Y ≃ a; Z ≃ b.
Comments:
2V small.
Chemistry of Englishite
Mindat Formula:
K3Na2Ca10Al15(PO4)21(OH)7 · 26H2O
Element Weights:
Crystallography of Englishite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Cell Parameters:
a = 38.43 Å, b = 11.86 Å, c = 20.67 Å
β = 111.25°
β = 111.25°
Ratio:
a:b:c = 3.24 : 1 : 1.743
Unit Cell V:
8,780.42 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Layers and aggregates of subparallel plates; friable masses.
Comment:
Class 2/m or m; Space Group A2/a or Aa.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 8.94 Å | (100) |
| 17.66 Å | (90) |
| 2.84 Å | (80) |
| 5.57 Å | (60) |
| 2.96 Å | (60) |
| 2.68 Å | (60) |
| 1.71 Å | (50) |
| 3.85 Å | (40) |
| 2.34 Å | (40) |
| 3.08 Å | (30) |
| 2.54 Å | (30) |
| 1.58 Å | (30) |
| 1.36 Å | (30) |
| 1.08 Å | (30) |
| 0.98 Å | (30) |
Comments:
Fairfield, Utah, USA. Data from Moore (1976).
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Near-surface Processes | |
| 21 : Chemically precipitated carbonate, phosphate, iron formations | |
| Stage 4b: Highly evolved igneous rocks | >3.0 |
| 34 : Complex granite pegmatites | |
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| 47c : [Carbonates, phosphates, borates, nitrates] |
Geological Setting:
Complex granitic pegmatite.
Type Occurrence of Englishite
General Appearance of Type Material:
Crusts in variscite nodules.
Place of Conservation of Type Material:
Harvard Unviersity, Cambridge, Massachusetts, USA: #95494.
Associated Minerals at Type Locality:
Other Language Names for Englishite
Common Associates
Associated Minerals Based on Photo Data:
| 37 photos of Englishite associated with Montgomeryite | Ca4MgAl4(PO4)6(OH)4 · 12H2O |
| 25 photos of Englishite associated with Tiptopite | K2(Na,Ca)2Li3Be6(PO4)6(OH)2 · H2O |
| 23 photos of Englishite associated with Roscherite | Ca2Mn2+5Be4(PO4)6(OH)4 · 6H2O |
| 13 photos of Englishite associated with Variscite | AlPO4 · 2H2O |
| 10 photos of Englishite associated with Crandallite | CaAl3(PO4)(PO3OH)(OH)6 |
| 10 photos of Englishite associated with Wardite | NaAl3(PO4)2(OH)4 · 2H2O |
| 7 photos of Englishite associated with Robertsite | Ca2Mn3+3(PO4)3O2 · 3H2O |
| 7 photos of Englishite associated with Hurlbutite | CaBe2(PO4)2 |
| 6 photos of Englishite associated with Beryl | Be3Al2(Si6O18) |
| 6 photos of Englishite associated with Whiteite-(CaMnMg) | {Ca}{Mn2+}{Mg2}{Al2}(PO4)4(OH)2 · 8H2O |
Related Minerals - Strunz-mindat Grouping
| 8.DH. | Thebaite-(NH4) | (NH4)3Al(C2O4)(PO3OH)2(H2O) |
| 8.DH. | Whiteite-(MnMnMn) | Mn2+Mn2+Mn2+2Al2(PO4)4(OH)2 · 8H2O |
| 8.DH. | Ferroberaunite | Fe2+Fe3+5(PO4)4(OH)5 · 6H2O |
| 8.DH. | Regerite | KFe6(PO4)4(OH)7(H2O)6 · 4H2O |
| 8.DH. | Ammoniotinsleyite | (NH4)Al2(PO4)2(OH) · 2H2O |
| 8.DH. | Dendoraite-(NH4) | (NH4)2NaAl(C2O4)(PO3OH)2(H2O)2 |
| 8.DH. | Rowleyite | [Na(NH4,K)9Cl4][V5+,4+2(P,As)O8]6 · n[H2O,Na,NH4,K,Cl] |
| 8.DH. | Hochleitnerite | Mn2Ti3(PO4)4O2(H2O)2 · 14H2O |
| 8.DH. | Whiteite-(CaMnFe) | CaMnFe2Al2(PO4)4(OH)2 · 8H2O |
| 8.DH.05 | Minyulite | KAl2(PO4)2F · 4H2O |
| 8.DH.10 | Leucophosphite | KFe3+2(PO4)2(OH) · 2H2O |
| 8.DH.10 | Tinsleyite | KAl2(PO4)2(OH) · 2H2O |
| 8.DH.10 | Spheniscidite | (NH4,K)(Fe3+,Al)2(PO4)2(OH) · 2H2O |
| 8.DH.15 | Jahnsite-(CaMnFe) | {Ca}{Mn2+}{Fe2+2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Jahnsite-(NaMnMn) | {Na}{Mn2+}{(Mn2+,Fe3+)2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Jahnsite-(CaMnMg) | {Ca}{Mn2+}{(Mg,Fe2+)2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Jahnsite-(CaMnMn) | {Ca}{Mn2+}{Mn2+2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Whiteite-(MnMnMg) | MnMnMg2Al2(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Jahnsite-(CaMnZn) | {Ca}{Mn2+}{Zn2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Jahnsite-(MnMnMg) | {Mn2+}{Mn2+}{Mg2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Jahnsite-(MnMnFe) | {Mn2+}{Mn2+}{Fe2+2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Jahnsite-(CaFeFe) | {Ca}{Fe2+}{Fe2+2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Rittmannite | {(Mn2+,Ca)}{Mn2+}{(Fe2+,Mn2+,Mg)2}{(Al,Fe3+)2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Keckite | CaMn2+(Fe3+Mn2+)Fe3+2(PO4)4(OH)3 · 7H2O |
| 8.DH.15 | Jahnsite-(NaMnMg) | {(Na,Ca)}{(Mn2+,Fe3+)}{(Mg,Fe3+)2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Jahnsite-(CaMgMg) | {Ca}{Mg}{Mg2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Jahnsite-(MnMnZn) | {Mn2+}{Mn2+}{Zn2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Whiteite-(CaMgMg) | CaMg3Al2(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Whiteite-(CaFeMg) | {Ca}{(Fe2+,Mn2+)}{Mg2}{Al2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Whiteite-(CaMnMg) | {Ca}{Mn2+}{Mg2}{Al2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Whiteite-(MnFeMg) | {(Mn2+,Ca)}{(Fe2+,Mn2+)}{Mg2}{Al2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Jahnsite-(MnMnMn) | {Mn2+}{Mn2+}{Mn2+2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Kaluginite | (Mn2+,Ca)MgFe3+(PO4)2(OH) · 4H2O |
| 8.DH.15 | Jahnsite-(CaFeMg) | {Ca}{Fe2+}{Mg2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Whiteite-(CaMnMn) | {Ca}{Mn2+}{Mn2}{Al2}(PO4)4(OH)2 · 8H2O |
| 8.DH.15 | Jahnsite-(NaFeMg) | {Na}{Fe3+}{Mg2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
| 8.DH.20 | Segelerite | Ca2 Mg2 Fe3+2(PO4)4(OH)2 · 8H2O |
| 8.DH.20 | Lun'okite | (Mn,Ca)(Mg,Fe,Mn)Al(PO4)2OH · 4H2O |
| 8.DH.20 | Manganosegelerite | (Mn2+,Ca)(Mn2+,Fe2+,Mg)Fe3+(PO4)2(OH) · 4H2O |
| 8.DH.20 | Wilhelmvierlingite | CaMnFe3+(PO4)2(OH) · 2H2O |
| 8.DH.20 | Juonniite | CaMgSc(PO4)2(OH) · 4H2O |
| 8.DH.20 | Overite | CaMgAl(PO4)2(OH) · 4H2O |
| 8.DH.25 | Calcioferrite | Ca2Fe3+2(PO4)3(OH) · 7H2O |
| 8.DH.25 | Zodacite | Ca4Mn2+Fe3+4(PO4)6(OH)4 · 12H2O |
| 8.DH.25 | Fanfaniite | Ca4MnAl4(PO4)6(OH)4 · 12H2O |
| 8.DH.25 | Kingsmountite | Ca3MnFeAl4(PO4)6(OH)4 · 12H2O |
| 8.DH.25 | Montgomeryite | Ca4MgAl4(PO4)6(OH)4 · 12H2O |
| 8.DH.30 | Pararobertsite | Ca2Mn3+3(PO4)3O2 · 3H2O |
| 8.DH.30 | Robertsite | Ca2Mn3+3(PO4)3O2 · 3H2O |
| 8.DH.30 | Arseniosiderite | Ca2Fe3+3(AsO4)3O2 · 3H2O |
| 8.DH.30 | Sailaufite | (Ca,Na,◻)2Mn3+3(AsO4)2(CO3)O2 · 3H2O |
| 8.DH.30 | Mitridatite | Ca2Fe3+3(PO4)3O2 · 3H2O |
| 8.DH.30 | Kolfanite | Ca2Fe3+3O2(AsO4)3 · 2H2O |
| 8.DH.35 | Mantienneite | KMg2Al2Ti(PO4)4(OH)3 · 15H2O |
| 8.DH.35 | Sperlingite | (H2O)K(Mn2+Fe3+)(Al2Ti)(PO4)4[O(OH)] [(H2O)9(OH)] · 4H2O |
| 8.DH.35 | Paulkerrite | K(Mg,Mn2+)2(Fe3+,Al,Ti,Mg)2Ti(PO4)4(OH)3 · 15H2O |
| 8.DH.35 | Hydroxylbenyacarite | (H2O)2Mn2(Ti2Fe)(PO4)4[O(OH)](H2O)10 · 4H2O |
| 8.DH.35 | Macraeite | K(H2O)Mn2(Fe2Ti)(PO4)4[O(OH)](H2O)10 · 4H2O |
| 8.DH.35 | Benyacarite | (H2O)2Mn2Ti2Fe3+(PO4)4(OF)(H2O)10 · 4H2O |
| 8.DH.35 | Fluormacraeite | [(H2O)K]Mn2(Fe2Ti)(PO4)4(OF)(H2O)10 · 4H2O |
| 8.DH.40 | Xanthoxenite | Ca4Fe3+2(PO4)4(OH)2 · 3H2O |
| 8.DH.45 | Mahnertite | NaCu3(AsO4)2Cl · 5H2O |
| 8.DH.50 | Andyrobertsite | KCdCu5(AsO4)4(H2AsO4) · 2H2O |
| 8.DH.50 | Calcioandyrobertsite | KCaCu5(AsO4)4(H2AsO4) · 2H2O |
| 8.DH.60 | Bouazzerite | Bi6(Mg,Co)11Fe3+14(AsO4)18(OH)4O12 · 86H2O |
| 8.DH.65 | Galliskiite | Ca4Al2(PO4)2F8 · 5H2O |
| 8.DH.70 | Joteite | Ca2CuAl(AsO4)[AsO3(OH)]2(OH)2 · 5H2O |
| 8.DH.75 | Kampelite | Ba6Mg3Sc8(PO4)12(OH)6 · 7H2O |
| 8.DH.80 | Kapundaite | NaCaFe4(PO4)4(OH)3 · 5H2O |
| 8.DH.85 | Vaniniite | Ca2Mn2+3Mn3+2O2(AsO4)4 · 2H2O |
Radioactivity
Radioactivity:
| Element | % Content | Activity (Bq/kg) | Radiation Type |
|---|---|---|---|
| Uranium (U) | 0.0000% | 0 | α, β, γ |
| Thorium (Th) | 0.0000% | 0 | α, β, γ |
| Potassium (K) | 3.3035% | 1,024 | β, γ |
For comparison:
- Banana: ~15 Bq per fruit
- Granite: 1,000–3,000 Bq/kg
- EU exemption limit: 10,000 Bq/kg
Note: Risk is shown relative to daily recommended maximum exposure to non-background radiation of 1000 µSv/year. Note that natural background radiation averages around 2400 µSv/year so in reality these risks are probably extremely overstated! With infrequent handling and safe storage natural radioactive minerals do not usually pose much risk.
Interactive Simulator:
Note: The mass selector refers to the mass of radioactive mineral present, not the full specimen, also be aware that the matrix may also be radioactive, possibly more radioactive than this mineral!
Activity: –
| Distance | Dose rate | Risk |
|---|---|---|
| 1 cm | ||
| 10 cm | ||
| 1 m |
The external dose rate (D) from a radioactive mineral is estimated by summing the gamma radiation contributions from its Uranium, Thorium, and Potassium content, disregarding daughter-product which may have a significant effect in some cases (eg 'pitchblende'). This involves multiplying the activity (A, in Bq) of each element by its specific gamma ray constant (Γ), which accounts for its unique gamma emissions. The total unshielded dose at 1 cm is then scaled by the square of the distance (r, in cm) and multiplied by a shielding factor (μshield). This calculation provides a 'worst-case' or 'maximum risk' estimate because it assumes the sample is a point source and entirely neglects any self-shielding where radiation is absorbed within the mineral itself, meaning actual doses will typically be lower. The resulting dose rate (D) is expressed in microsieverts per hour (μSv/h).
D = ((AU × ΓU) + (ATh × ΓTh) + (AK × ΓK)) / r2 × μshield
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 Englishite
mindat.org URL:
https://www.mindat.org/min-1383.html
Please feel free to link to this page.
Please feel free to link to this page.
Search Engines:
External Links:
Mineral Dealers:
References for Englishite
Reference List:
Larsen, Esper S., Shannon, Earl V. (1930) The minerals of the phosphate nodules from near Fairfield, Utah. American Mineralogist, 15 (8) 307-337
Larsen, Esper S., 3d, (1942) The mineralogy and paragenesis of the variscite nodules from near Fairfield, Utah, Part 1. American Mineralogist, 27 (4) 281-300
Moore, Paul Brian (1976) Derivative structures based on the alunite octahedral sheet: mitridatite and englishite. Mineralogical Magazine, 40 (316) 863-866 doi:10.1180/minmag.1976.040.316.07
Dunn, Peter J., Rouse, R. C., Nelen, J. A. (1984) Englishite: new chemical data and a second occurrence, from the Tip Top pegmatite, Custer, South Dakota. The Canadian Mineralogist, 22 (3) 469-470
Localities for Englishite
symbol to view information about a locality.
The 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).
All localities listed without proper references should be considered as questionable.
USA | |
| Jensen (1999) |
| Jensen et al. (1995) |
| Jensen et al. (1995) |
| Castor et al. (2004) |
| Dunn et al. (1984) +1 other reference |
| Palache et al. (1951) +1 other reference |
| Thorne (n.d.) +1 other reference |
Quick NavTopAbout EnglishiteUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography X-Ray Powder DiffractionGeological EnvironmentType Occurrence Other LanguagesCommon AssociatesStrunz-MindatRadioactivityOther InformationInternet Links References Localities Locality List
Tip Top Mine, Fourmile, Custer Mining District, Custer County, South Dakota, USA