Kayrobertsonite
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About Kayrobertsonite
Formula:
[MnAl2(PO4)2(OH)2(H2O)4]·2H2O
Colour:
Snow-white
Crystal System:
Triclinic
Name:
Named in honor of Kay Robertson (born Gabriella Katherine Loewi) (b. 23 April 1920, Venice, Italy) of Los Angeles, California, USA, a well known collector, especially of German localities, since the 1950s. She was a founding member of the Southern California Micromineralogists Society.
The OH analogue of nordgauite. Structural topology similar to that of nordgauite, but with double amount of water molecules in the [001] channels.
Classification of Kayrobertsonite
Physical Properties of Kayrobertsonite
Colour:
Snow-white
Optical Data of Kayrobertsonite
Type:
Biaxial (-)
RI values:
nα = 1.530(1) nβ = 1.554(1) nγ = 1.566(1)
2V:
Measured: 70.3° (5), Calculated: 69.6°
Max Birefringence:
δ = 0.036

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
Pleochroism:
Non-pleochroic
Chemical Properties of Kayrobertsonite
Formula:
[MnAl2(PO4)2(OH)2(H2O)4]·2H2O
IMA Formula:
MnAl2(PO4)2(OH)2 · 6H2O
Crystallography of Kayrobertsonite
Crystal System:
Triclinic
Class (H-M):
1 - Pinacoidal
Space Group:
P1
Setting:
P1
Cell Parameters:
a = 10.049(2) Å, b = 10.205(2) Å, c = 6.083(1) Å
α = 91.79(3)°, β = 99.70(3)°, γ = 98.02(3)°
α = 91.79(3)°, β = 99.70(3)°, γ = 98.02(3)°
Ratio:
a:b:c = 0.985 : 1 : 0.596
Unit Cell V:
607.9 ų
Z:
2
Morphology:
Intergrown masses offibrous needles up to 100 μm long and less than 5 μm wide
X-Ray Powder Diffraction
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
10.047 | (100) |
9.804 | (8) |
7.629 | (44) |
5.029 | (12) |
4.695 | (10) |
3.023 | (12) |
2.952 | (10) |
2.579 | (10) |
Type Occurrence of Kayrobertsonite
Co-Type Localities:
General Appearance of Type Material:
intergrown masses of snow-white, soft, finely fibrous needles, less than 5 μm in diameter and no more than 100 μm in length
Place of Conservation of Type Material:
Co-type material is deposited in the mineralogical collections of the Museum Victoria, Melbourne, Victoria, Australia, registered numbers M53379, M53380 and M48795, and the Natural History Museum of Los Angeles County, Los Angeles, CA 90007, USA, registr
Geological Setting of Type Material:
pegmatites
Reference:
Mills, S.J., Grey, I.E., Kampf, A.R., Birch, W.D., MacRae, C.M., Smith, J.B., Keck, E. (2016) Kayrobertsonite, MnAl2(PO4)2(OH)2·6H2O, a new phosphate mineral related to nordgauite. European Journal of Mineralogy: 28: 649-654.
Synonyms of Kayrobertsonite
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 Kayrobertsonite
Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Mills, S.J., Grey, I.E., Kampf, A.R., Birch, W.D., MacRae, C.M., Smith, J.B. and Keck, E. (2015) Kayrobertsonite, IMA 2015- 029. CNMNC Newsletter No. 26, August 2015, page 944. Mineralogical Magazine: 79: 941-947.
Mills, S.J., Grey, I.E., Kampf, A.R., Birch, W.D., MacRae, C.M., Smith, J.B., Keck, E. (2016) Kayrobertsonite, MnAl2(PO4)2(OH)2·6H2O, a new phosphate mineral related to nordgauite. European Journal of Mineralogy: 28: 649-654.
Internet Links for Kayrobertsonite
mindat.org URL:
https://www.mindat.org/min-46697.html
Please feel free to link to this page.
Please feel free to link to this page.
External Links:
Mineral Dealers:
Localities for Kayrobertsonite
Locality List




All localities listed without proper references should be considered as questionable.
Germany (TL) | |
| Mills, S.J., Grey, I.E., Kampf, A.R., Birch, W.D., MacRae, C.M., Smith, J.B. and Keck, E. (2015) Kayrobertsonite, IMA 2015- 029. CNMNC Newsletter No. 26, August 2015, page 944; Mineralogical Magazine, 79, 941-947: Mills, S.J., Grey, I.E., Kampf, A.R., Birch, W.D., MacRae, C.M., Smith, J.B., Keck, E. (2016): Kayrobertsonite, MnAl2(PO4)2(OH)2·6H2O, a new phosphate mineral related to nordgauite. European Journal of Mineralogy, 28, 649-654. |
USA (TL) | |
| Mills, S.J., Grey, I.E., Kampf, A.R., Birch, W.D., MacRae, C.M., Smith, J.B. and Keck, E. (2015) Kayrobertsonite, IMA 2015- 029. CNMNC Newsletter No. 26, August 2015, page 944; Mineralogical Magazine, 79, 941-947.;Mills, S.J., Grey, I.E., Kampf, A.R., Birch, W.D., MacRae, C.M., Smith, J.B., Keck, E. (2016): Kayrobertsonite, MnAl2(PO4)2(OH)2·6H2O, a new phosphate mineral related to nordgauite. European Journal of Mineralogy, 28, 649-654. |
Foote Lithium Co. Mine, Kings Mountain District, Cleveland Co., North Carolina, USA