Hydrokenoralstonite
A valid IMA mineral species - grandfathered
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About Hydrokenoralstonite
Formula:
Na0.5(Al,Mg)2(F,OH)6 · H2O
Colour:
Colourless, white
Lustre:
Vitreous
Hardness:
5
Specific Gravity:
2.56 - 2.62
Crystal System:
Isometric
Member of:
Name:
Originally named ralstonite in honor of Rev. J. Grier Ralston (December 28, 1815 - November 10, 1880), of Norristown, Pennsylvania, USA, who first observed the mineral. Renamed to hydrokenoralstonite after being moved into the pyrochlore supergroup (Atencio et al. 2017).
Renamed from ralstonite after being moved into the Pyrochlore Supergroup (IMA July 2016; Atencio et al., 2017).
The earlier reported "AHF" phase (hydrated aluminum hydroxy-fluoride) and the "ralstonite-like mineral" (Desborough & Rostad, 1980; Keith, 1991; Rosenberg 2006) are also hydrokenoralstonite.
Compare fluornatrocoulsellite and UM1941-01-F:AlCaHMgNa.
The earlier reported "AHF" phase (hydrated aluminum hydroxy-fluoride) and the "ralstonite-like mineral" (Desborough & Rostad, 1980; Keith, 1991; Rosenberg 2006) are also hydrokenoralstonite.
Compare fluornatrocoulsellite and UM1941-01-F:AlCaHMgNa.
Unique Identifiers
Mindat ID:
3354
Long-form identifier:
mindat:1:1:3354:7
IMA Classification of Hydrokenoralstonite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
◻2Al2F6(H2O)
First published:
1871
Classification of Hydrokenoralstonite
3.CF.05
3 : HALIDES
C : Complex halides
F : Tekto-aluminofluorides
3 : HALIDES
C : Complex halides
F : Tekto-aluminofluorides
11.6.12.1
11 : HALIDE COMPLEXES
6 : Aluminofluorides - Isolated Octahedra
11 : HALIDE COMPLEXES
6 : Aluminofluorides - Isolated Octahedra
8.6.9
8 : Halides - Fluorides, Chlorides, Bromides and Iodides; also Fluoborates and Fluosilicates
6 : Halides of Al
8 : Halides - Fluorides, Chlorides, Bromides and Iodides; also Fluoborates and Fluosilicates
6 : Halides of Al
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 for Standard |
|---|---|---|
| Hkra | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Pronunciation of Hydrokenoralstonite
Pronunciation:
| Play | Recorded by | Country |
|---|---|---|
| Jolyon Ralph | United Kingdom |
Physical Properties of Hydrokenoralstonite
Vitreous
Transparency:
Transparent, Translucent
Colour:
Colourless, white
Streak:
White
Hardness:
5 on Mohs scale
Comment:
Typically given as Mohs 4.5. A modern measurement is made by Pauly (1985).
Tenacity:
Brittle
Cleavage:
Imperfect/Fair
On {111}.
On {111}.
Fracture:
Irregular/Uneven
Density:
2.56 - 2.62 g/cm3 (Measured)
Optical Data of Hydrokenoralstonite
Type:
Isotropic
RI values:
n = 1.399 - 1.427
Birefringence:
Frequently exhibits weak anomalous birefringence, with the crystals divided into eight uniaxial (or biaxial) sectors, or otherwise.
Surface Relief:
Very High (negative)
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Chemistry of Hydrokenoralstonite
Mindat Formula:
Na0.5(Al,Mg)2(F,OH)6 · H2O
Element Weights:
Crystallography of Hydrokenoralstonite
Crystal System:
Isometric
Class (H-M):
m3m(4/m32/m) - Hexoctahedral
Space Group:
Fd3m
Cell Parameters:
a = 9.91(4) Å
Unit Cell V:
973.24 ų (Calculated from Unit Cell)
Z:
8
Morphology:
Crystals octahedral, often with small {001}; less often cubo-octahedral, or cubic with small {111}.
Comment:
SG Fd-3m. Atencio et al. (2017) give a = 9.8455(7) Å.
Crystal Structure
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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) |
|---|---|---|---|---|---|---|---|
| 0014784 | Hydrokenoralstonite | Effenberger H, Kluger F (1984) Ralstonite: a contribution to the knowledge of composition and crystal structure Neues Jahrbuch fur Mineralogie, Monatshefte 1984 97-108 | 1984 | Ivigtut, Greenland | 0 | 293 | |
| 0000023 | Hydrokenoralstonite | Pabst A (1939) Formula and structure of ralstonite American Mineralogist 24 566-576 |  | 1939 | Ivigtut, Greenland | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 5.74 Å | (100) |
| 1.765 Å | (86) |
| 2.88 Å | (75) |
| 3.01 Å | (53) |
| 1.508 Å | (40) |
| 1.923 Å | (38) |
| 2.29 Å | (32) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Near-surface Processes | |
| 23 : Subaerial aqueous alteration by non-redox-sensitive fluids (see also #47) | |
| Stage 4b: Highly evolved igneous rocks | >3.0 |
| 34 : Complex granite pegmatites | |
| Stage 7: Great Oxidation Event | <2.4 |
| 45b : [Other oxidized fumarolic minerals] |
Type Occurrence of Hydrokenoralstonite
General Appearance of Type Material:
octahedral crystals to 1.5mm
Place of Conservation of Type Material:
Yale University, New Haven, Connecticut, USA, 1.4437.
Associated Minerals at Type Locality:
Synonyms of Hydrokenoralstonite
Other Language Names for Hydrokenoralstonite
Dutch:Hydrokenoralstoniet
German:Hydrokenoralstonit
Ralstonit
Ralstonit
Russian:Ральстонит
Simplified Chinese:氟钠镁铝石
Spanish:Ralstonita
Traditional Chinese:氟鈉鎂鋁石
Relationship of Hydrokenoralstonite to other Species
Member of:
Common Associates
Associations Based on Photo Data:
| 85 photos of Hydrokenoralstonite associated with Thomsenolite | NaCa[AlF6] · H2O |
| 22 photos of Hydrokenoralstonite associated with Pachnolite | NaCa[AlF6] · H2O |
| 21 photos of Hydrokenoralstonite associated with Cryolite | Na2NaAlF6 |
| 20 photos of Hydrokenoralstonite associated with Prosopite | CaAl2F4[(OH)4-xFx] |
| 19 photos of Hydrokenoralstonite associated with Siderite | FeCO3 |
| 16 photos of Hydrokenoralstonite associated with Quartz | SiO2 |
| 11 photos of Hydrokenoralstonite associated with 'Limonite' | |
| 7 photos of Hydrokenoralstonite associated with Elpasolite | K2NaAlF6 |
| 7 photos of Hydrokenoralstonite associated with Wulfenite | Pb(MoO4) |
| 6 photos of Hydrokenoralstonite associated with 'Amazonite' | K(AlSi3O8) |
Related Minerals - Strunz-mindat Grouping
| 3.CF.10 | 'UM1941-01-F:AlCaHMgNa' | NaCaMgAl3F14 · 4H2O |
| 3.CF.15 | Bøgvadite | Na2SrBa2Al4F20 |
Other Information
Notes:
Decomposed by HF with evolution of HF.
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 Hydrokenoralstonite
mindat.org URL:
https://www.mindat.org/min-3354.html
Please feel free to link to this page.
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Mineral Dealers:
References for Hydrokenoralstonite
Reference List:
Bøggild, O.B. (1912) Iagttagelser over Kryolitgruppens Mineraler [Observations on the Minerals of the Cryolite Group]. Meddelelser om Grønland, 50 (3).
Ferguson, R. B. (1949) Observations on some aluminium fluoride minerals. American Mineralogist, 34 (5-6) 383-397
Pauly, Hans (1965) Ralstonite from Ivigtut, South Greenland. American Mineralogist, 50 (11-12) 1851-1864
Pauly, Hans (1985) Hardness of cryolite, chiolite, cryolithionite and other fluorides from Ivigtut, South Greenland. Bulletin of the Geological Society of Denmark, 34. 145-150 doi:10.37570/bgsd-1985-34-13
Birch, W. D., Pring, A. (1990) A calcian ralstonite-like mineral from the Cleveland Mine, Tasmania, Australia. Mineralogical Magazine, 54 (377) 599-602 doi:10.1180/minmag.1990.054.377.11
Rosenberg, P. E. (2006) Stability relations of aluminum hydroxy-fluoride hydrate, a ralstonite-like mineral, in the system AlF3-Al2O3-H2O-HF. The Canadian Mineralogist, 44 (1). 125-134 doi:10.2113/gscanmin.44.1.125
Localities for Hydrokenoralstonite
Showing 76 localities.
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.
Antarctica | |
| Rosenberg (1988) +1 other reference |
| Viramonte et al. (1974) |
Australia | |
| Peter Elliott |
| Am Min 85:231-235 +1 other reference |
| Bottrill +1 other reference |
Bolivia | |
| Walenta et al. (1980) |
Brazil | |
| Minuzzii et al. (2003) +1 other reference |
| Wegner et al. (1998) +1 other reference |
Cape Verde | |
| Universidade de Evora +1 other reference |
Costa Rica | |
| Stoiber et al. (1974) |
| Rodríguez et al. (2017) |
El Salvador | |
| Stoiber et al. (1974) |
Finland | |
| Ilkka Mikkola collection |
| Lahti Seppo I. 2011. Kotkan ... | |
France | |
| Vlastélic et al. (2013) |
Germany | |
| Möhn et al. (12/2021) |
| Witzke et al. (2015) |
| Möhn et al. (10/2020) |
Greece | |
| Gröbner et al. (2002) |
| Gröbner et al. (2002) |
Greenland (TL) | |
| Brush (1871) +3 other references |
Guatemala | |
| Stoiber et al. (1974) |
Iceland | |
| Balić-Žunić et al. (2016) |
| Garavelli et al. (2010) |
| Mitolo et al. (2008) +1 other reference |
| Jakobsson et al. (1992) |
Italy | |
| Di Girolamo (1968) |
| Russo et al. (2004) |
| Russo et al. (2004) | |
| Guastoni A. et al. (2013) |
| Brizzi G. et al. (1988) +1 other reference |
Japan | |
| Africano et al. (2000) |
| Africano et al. (2000) | |
| Jimbo (1899) +1 other reference |
Nicaragua | |
| Stoiber et al. (1974) |
Nigeria | |
| - (2002) |
Norway | |
| Raade et al. (1980) +1 other reference |
Poland | |
| Kruszewski (2012) |
Russia | |
| Bailey (1980) |
| Ripp et al. (1996) +1 other reference |
| Bailey (1980) +1 other reference |
| Raade et al. (1980) | |
| Gurbanov et al. (2008) |
| Vergasova et al. (2007) |
| Pekov et al. (2015) | |
| L. P. Vergasova et al. (2006) | |
| Sharygin et al. (2018) +1 other reference |
| Pekov (1998) |
| Vergasova et al. (1977) +1 other reference |
| Pavel M. Kartashov (n.d.) |
| P.M. Karashov data +1 other reference |
Saint Helena， Ascension and Tristan da Cunha | |
| Bailey (1980) | |
South Africa | |
| Atanasova et al. (2016) |
Spain | |
| Campeny et al. (2023) |
Switzerland | |
| Kolitsch (1998) +1 other reference |
Ukraine | |
| Liventseva (n.d.) +2 other references |
USA | |
| Keith (1991) |
| Graeme (1993) |
| Graeme (1993) +1 other reference |
| Graeme (1993) | |
| Hanson et al. (2008) |
| Cross et al. (1883) +1 other reference |
| Gross et al. (1966) | |
| Pavel M. Kartashov analytical data | |
| Gross et al. (1966) | |
| Armbrustmacher (1988) +1 other reference |
| Naughton et al. (1976) |
| Hon et al. (2009) | |
| Desborough et al. (1980) |
| Castor et al. (2004) |
| Castor et al. (2004) |
| Mandarino (2000) |
| American Mineralogist: 72: 1122-1130. |
| |
| Rocks & Minerals: 73 (3) | |
| Kearns (1995) +2 other references |
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Ivigtut Mine, Ivigtut stock, Arsuk Fjord, Sermersooq, Greenland