Gearksutite
A valid IMA mineral species - grandfathered
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About Gearksutite
Formula:
Ca[Al(F,OH)5(H2O)]
Colour:
white, pale rose, colourless (including in transmitted light)
Lustre:
Dull
Hardness:
2
Specific Gravity:
2.768
Crystal System:
Triclinic
Name:
From the Greek γή, earth, and arksutite (chiolite), which it was thought to resemble in composition, in allusion to the earthy character of the material.
Unique Identifiers
Mindat ID:
1663
Long-form identifier:
mindat:1:1:1663:2
IMA Classification of Gearksutite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
CaAlF4(OH) · H2O
Classification of Gearksutite
3.CC.05
3 : HALIDES
C : Complex halides
C : Soro-aluminofluorides
3 : HALIDES
C : Complex halides
C : Soro-aluminofluorides
11.6.8.1
11 : HALIDE COMPLEXES
6 : Aluminofluorides - Isolated Octahedra
11 : HALIDE COMPLEXES
6 : Aluminofluorides - Isolated Octahedra
8.6.12
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 |
|---|---|---|
| Gak | 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 Gearksutite
Dull
Transparency:
Transparent, Opaque
Colour:
White, pale rose, colourless (including in transmitted light)
Comment:
Transparent in thin fibers
Streak:
White
Hardness:
2 on Mohs scale
Cleavage:
Imperfect/Fair
On {110}.
On {110}.
Density:
2.768 g/cm3 (Measured) 2.771 g/cm3 (Calculated)
Optical Data of Gearksutite
Type:
Biaxial (-)
RI values:
nα = 1.448 nβ = 1.454 nγ = 1.456
Max. Birefringence:
δ = 0.008
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 distinct
Chemistry of Gearksutite
Mindat Formula:
Ca[Al(F,OH)5(H2O)]
Element Weights:
Crystallography of Gearksutite
Crystal System:
Triclinic
Class (H-M):
1 - Pinacoidal
Space Group:
P1
Cell Parameters:
a = 4.940(1) Å, b = 6.810(1) Å, c = 6.978(1) Å
α = 101.12°, β = 94.86°, γ = 110.07°
α = 101.12°, β = 94.86°, γ = 110.07°
Ratio:
a:b:c = 0.725 : 1 : 1.025
Unit Cell V:
213.43 ų
Z:
2
Morphology:
Massive; nodular with an earthy to chalky character. Consisting of very minute needles with inclined extinction.
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) |
|---|---|---|---|---|---|---|---|
| 0002346 | Gearksutite | Marchetti F, Perchiazzi N (2000) The crystal structure of gearksutite, CaAlF4(OH).H2O American Mineralogist 85 231-235 |  | 2000 | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Loading XRD data...
Data courtesy of RRUFF project at University of Arizona, used with permission.
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 4.54 Å | (10) |
| 3.33 Å | (7d) |
| 3.14 Å | (8) |
| 2.28 Å | (8) |
| 2.15 Å | (6) |
| 1.924 Å | (8) |
| 1.741 Å | (6) |
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 Gearksutite
Synonyms of Gearksutite
Other Language Names for Gearksutite
Dutch:Gearksutiet
German:Gearksutit
Russian:Геарксутит
Simplified Chinese:氟铝钙矿
Spanish:Gearksutita
Traditional Chinese:氟鋁鈣礦
Common Associates
Associated Minerals Based on Photo Data:
| 21 photos of Gearksutite associated with Creedite | Ca3Al2(SO4)(OH)2F8 · 2H2O |
| 16 photos of Gearksutite associated with Fluorite | CaF2 |
| 12 photos of Gearksutite associated with Quartz | SiO2 |
| 10 photos of Gearksutite associated with Prosopite | CaAl2F4[(OH)4-xFx] |
| 7 photos of Gearksutite associated with Linarite | PbCu(SO4)(OH)2 |
| 6 photos of Gearksutite associated with Weberite | Na2Mg[AlF6]F |
| 4 photos of Gearksutite associated with Gypsum | CaSO4 · 2H2O |
| 3 photos of Gearksutite associated with Siderite | FeCO3 |
| 3 photos of Gearksutite associated with Serpierite | Ca(Cu,Zn)4(SO4)2(OH)6 · 3H2O |
| 3 photos of Gearksutite associated with Cerussite | PbCO3 |
Related Minerals - Strunz-mindat Grouping
| 3.CC.10 | Acuminite | Sr[AlF4(OH)(H2O)] |
| 3.CC.10 | Tikhonenkovite | Sr[AlF4(OH)(H2O)] |
| 3.CC.15 | Artroeite | Pb[AlF3(OH)2] |
| 3.CC.20 | Jarlite | Na(Sr,Na)7MgAl6F32(OH,H2O)2 |
| 3.CC.20 | Calcjarlite | Na(Ca,Sr)3Al3(OH)2F14 |
| 3.CC.20 | Jørgensenite | Na2(Sr,Ba)14Na2Al12F64(OH,F)4 |
Fluorescence of Gearksutite
Compact, massive material fluoresces dark violet to bluish gray; powdery material fluoresces yellowish brown.
Other Information
Notes:
Readily soluble in dilute acid.
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 Gearksutite
mindat.org URL:
https://www.mindat.org/min-1663.html
Please feel free to link to this page.
Please feel free to link to this page.
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Mineral Dealers:
References for Gearksutite
Reference List:
Bøggild, O.B. (1912) Iagttagelser over Kryolitgruppens Mineraler [Observations on the Minerals of the Cryolite Group]. Meddelelser om Grønland, 50 (3).
Simpson, E.S. (1920) On Gearksutite at Gingin, Western Australia. Mineralogical Magazine: 19: 23-39.
Larsen, Esper S. (1921) The microscopic determination of the nonopaque minerals. Bulletin 679. US Geological Survey doi:10.3133/b679 p.78
Fleischer, M., Rooseboom, E. H., Skinner, Brian (1960) New Mineral Names; New data; Discredited minerals. American Mineralogist, 45 (9-10) 1130-1136
(1962) International Mineralogical Association: Commission on New Minerals and Mineral Names. Mineralogical Magazine and Journal of the Mineralogical Society, 33 (258) 260-263 doi:10.1180/minmag.1962.033.258.09
Marchetti, Fabio, Perchiazzi, Natale (2000) The crystal structure of gearksutite, CaAlF4(OH)·H2O. American Mineralogist, 85 (1) 231-235 doi:10.2138/am-2000-0123
Localities for Gearksutite
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.
Australia | |
| Am Min 85:231-235 +1 other reference |
| Edward S. Simpson (1920) +1 other reference |
Austria | |
| Program and Abstracts Volume +2 other references |
| Kolitsch (2016) |
Bolivia | |
| Walenta et al. (1980) +1 other reference |
Brazil | |
| JENKINS II (1987) |
China | |
| Niedermayr (2004) |
| Mingyue He et al. (2002) |
Finland | |
| Ilkka Mikkola collection |
France | |
| Pascal Chollet collection |
Germany | |
| 58 +5 other references |
| Gröbner et al. (2011) |
| Möhn et al. (07/2020) |
Greece | |
| |
| Wendel (2000) +2 other references | |
| Kolitsch et al. (2014) |
| Rieck (n.d.) |
Greenland (TL) | |
| Palache et al. (1951) +2 other references |
Italy | |
| Russo et al. (2014) +1 other reference |
| Russo et al. (2011) +2 other references |
| Campostrini et al. (2019) | |
| Russo et al. (2014) +1 other reference | |
| Bortolozzi et al. (2018) |
| Prof. P. Orlandi personal communication ... |
| Bernauer (1941) |
| Campostrini et al. (2011) | |
| Bernauer (1941) +2 other references | |
| Bortolozzi et al. (2021) |
| - (n.d.) |
| Biagioni et al. (2013) |
| Biagioni et al. (2013) | |
| Menchetti et al. (2015) |
| Boscardin M. et al. (1995) +1 other reference |
| American Mineralogist | |
| Pegoraro S. (2014) | |
| Neschen (n.d.) |
Kazakhstan | |
| Pavel.M. Kartashov (n.d.) +1 other reference |
| Evseev (1995) +2 other references |
| Pavel.M. Kartashov (n.d.) |
Kyrgyzstan | |
| Kolesar et al. (1993) |
Mexico | |
| Megaw (2023) |
| Panczner (1987) |
Norway | |
| Dietrich et al. (1965) +1 other reference |
Russia | |
| Bailey (1980) |
| Arkhipchuk (1971) | |
| Ripp et al. (1996) +1 other reference |
| webmineral.ru (2016) |
| M.M. Povilaitis data (http://klopotow.narod.ru/mindata/locathn/R_Buryat/zakamensk/djida.html) | |
| Bailey (1980) +1 other reference |
| Pekov (1998) |
| Pekov (1998) |
| Bailey (1980) |
| Pavel.M. Kartashov (n.d.) +1 other reference | |
| Pavel.M. Kartashov (n.d.) |
| P.M. Karashov data |
South Africa | |
| Cairncross et al. (1995) +1 other reference |
| Robert O. Meyer collection +2 other references |
Spain | |
| Calvo (2006) |
| Rodríguez +4 other references |
| Rosell et al. (2017) |
UK | |
| Norman Wilson collection |
| Norman Wilson personal collection |
Ukraine | |
| Yurk Yu.Yu. et al. (1973) +1 other reference |
USA | |
| Rob Bowell |
| Rob Bowell | |
| Jones (1980) +1 other reference |
| Eckel et al. (1997) |
| Eckel et al. (1997) | |
| Eckel et al. (1997) |
| Palache et al. (1951) +1 other reference |
| Gross et al. (1966) | |
| Pavel M. Kartashov analytical data (2012) | |
| Gross et al. (1966) | |
| Eckel et al. (1997) |
| Palache et al. (1951) +1 other reference |
| 2009 New Mexico Mineral Symposium ... +1 other reference |
| Castor et al. (2004) |
| Walstrom (n.d.) +1 other reference |
| Castor et al. (2004) |
| Castor et al. (2004) |
| Castor et al. (2004) |
| Bullock (1981) |
| Bullock (1981) |
| Bullock (1981) |
| Kearns et al. (2000) |
| The System of Mineralogy of James ... +3 other references |
| Lasmanis (1983) |
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