Nafeasite
A valid IMA mineral species
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About Nafeasite
Formula:
Na3Fe3+3(AsO3OH)6 · 3H2O
Colour:
Light to medium pink
Lustre:
Vitreous
Hardness:
2½
Specific Gravity:
3.23 (Calculated)
Crystal System:
Monoclinic
Name:
Named for the composition, including sodium (Latin, NAtrium), iron (Latin, FErrum), and arsenic (= As).
Dimorph of:
New structure type. The Fe analogue of naalasite. First Na-Fe hydroxyarsenate among minerals. Compare, e.g., natropharmacosiderite and yazganite; also khrenovite and yurmarinite.
The structure is based on alternating AsO3(OH) tetrahedra and Fe3+O6 octahedra.
The structure is based on alternating AsO3(OH) tetrahedra and Fe3+O6 octahedra.
Unique Identifiers
Mindat ID:
55953
Long-form identifier:
mindat:1:1:55953:9
Similar Names
| Nifesite | A mixture of two or more distinct mineral species |
IMA Classification of Nafeasite
Classification of Nafeasite
8.CF.
8 : PHOSPHATES, ARSENATES, VANADATES
C : Phosphates without additional anions, with H2O
F : With large and medium-sized cations, RO4:H2O > 1:1
8 : PHOSPHATES, ARSENATES, VANADATES
C : Phosphates without additional anions, with H2O
F : With large and medium-sized cations, RO4:H2O > 1:1
Mineral Symbols
As of 2021 there are now IMAâCNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Nfa | IMAâCNMNC | Warr, L.N. (2021). IMAâCNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Nafeasite
Vitreous
Transparency:
Transparent
Colour:
Light to medium pink
Streak:
White
Hardness:
2½ on Mohs scale
Comment:
ca.
Density:
3.23(2) g/cm3 (Calculated)
Optical Data of Nafeasite
Type:
Biaxial (+)
RI values:
nα = 1.679(3) nβ = 1.682(3) nγ = 1.730(5)
2V:
Measured: 27° (2)
Max. Birefringence:
δ = 0.051
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 Âĩm 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. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
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 Âĩm 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. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
Very High (positive)
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
Interference Figure:
This shows the idealized biaxial acute bisectrix (Bxa) interference figure
- the conoscopic view for a grain cut perpendicular to the acute bisectrix, using
this mineral's 2V. The two small white dots mark the melatopes - the points
where the two optic axes emerge - and are shown only when they fall within the
field of view. The coloured bands are isochromatics, and the dark bands are
isogyres.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Dispersion:
slight, r < v
Chemistry of Nafeasite
Mindat Formula:
Na3Fe3+3(AsO3OH)6 · 3H2O
Element Weights:
Crystallography of Nafeasite
Crystal System:
Monoclinic
Class (H-M):
2 - Sphenoidal
Space Group:
B2
Setting:
C2
Cell Parameters:
a = 18.688(2) Å, b = 8.6769(7) Å, c = 14.810(1) Å
β = 105.238(5)°, γ = 18.688(2)°
β = 105.238(5)°, γ = 18.688(2)°
Ratio:
a:b:c = 2.154 : 1 : 1.707
Unit Cell V:
2,317.07 Ã
Âģ (Calculated from Unit Cell)
Z:
12
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 9.04 Ã | (20) |
| 7.23 Ã | (89) |
| 4.33 Ã | (30) |
| 3.127 Ã | (100) |
| 3.085 Ã | (33) |
| 2.809 Ã | (15) |
| 2.518 Ã | (15) |
| 1.417 Ã | (16) |
Comments:
From Type Description.
Type Occurrence of Nafeasite
General Appearance of Type Material:
Equant crystals in tightly intergrown aggregates.
Place of Conservation of Type Material:
Type material is deposited in the collections of the Mineralogisches Museum Hamburg, Leibniz-Institut zur Analyse des BiodiversitÃĪtswandels, Grindelallee 48, 20146 Hamburg, Germany, catalogue number MD760 (holotype), and the Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, CA 90007, USA, catalogue numbers 76193 (piece of the holotype) and 76194 (cotype).
Geological Setting of Type Material:
Weathering zone.
Associated Minerals at Type Locality:
Synonyms of Nafeasite
Other Language Names for Nafeasite
Related Minerals - Strunz-mindat Grouping
| 8.CF. | Ferraioloite | MgMn2+4(Fe2+0.5Al3+0.5)4Zn4(PO4)8(OH)4(H2O)20 |
| 8.CF. | Naalasite | NaAl(AsO3OH)2 · H2O |
| 8.CF. | Falsterite | Ca2MgMn2+2Fe2+2Fe3+2Zn4(PO4)8(OH)4(H2O)14 |
| 8.CF. | Espadaite | Na4Ca3Mg2[AsO3(OH)]2[AsO2(OH)2]10 · 7H2O |
| 8.CF. | Liraite | NaCa2Mn2+2[Fe3+Fe2+]Mn2+2(PO4)6(H2O)2 |
| 8.CF.05 | Tassieite | (Na,âŧ)Ca2(Mg,Fe2+,Fe3+)2(Fe2+,Mg)2(Fe3+,Mg)2(PO4)6 · 2H2O |
| 8.CF.05 | Bederite | Ca2(Mn2+)4(Fe3+)2(PO4)6 · 2H2O |
| 8.CF.05 | Wicksite | NaCa2(Fe2+,Mn2+)4MgFe3+(PO4)6 · 2H2O |
| 8.CF.05 | Grischunite | NaCa2Mn2+5Fe3+(AsO4)6 · 2H2O |
| 8.CF.05 | Maneckiite | (Naâŧ)Ca2Fe2+2(Fe3+Mg)Mn2(PO4)6 · 2H2O |
| 8.CF.10 | Haigerachite | KFe3+3(PO3OH)2[PO2(OH)2]6 · 4H2O |
| 8.CF.10 | Yazganite | NaFe3+2(Mg,Mn2+)(AsO4)3 · H2O |
| 8.CF.15 | Currierite | Na4Ca3MgAl4(AsO3OH)12 · 9H2O |
| 8.CF.20 | RÃosecoite | Ca2Mg(AsO3OH)3(H2O)2 |
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 Nafeasite
mindat.org URL:
https://www.mindat.org/min-55953.html
Please feel free to link to this page.
Please feel free to link to this page.
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External Links:
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References for Nafeasite
Reference List:
Miyawaki, Ritsuro, Hatert, FrÃĐdÃĐric, Pasero, Marco, Mills, Stuart J. (2022) IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) â Newsletter 66. European Journal of Mineralogy, 34 (2) 253-257 doi:10.5194/ejm-34-253-2022
Kampf, Anthony R., SchlÞter, Jochen, Malcherek, Thomas, Paulenz, Bianca, Pohl, Dieter, Ma, Chi, Dini, Maurizio, Molina Donoso, Arturo A. (2022) Nafeasite, NaFe3+(AsO3OH)2â
H2O, a new framework arsenate from the Torrecillas mine, Iquique Province, Chile. Mineralogical Magazine, 86 (6) 883-890 doi:10.1180/mgm.2022.58
Localities for Nafeasite
Showing 1 localities.
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
â - 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.
Chile (TL) | |
| Miyawaki et al. (2022) |
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Torrecillas mine, Iquique, Iquique Province, TarapacÃĄ, Chile