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Wagnerite-Ma5bc
A structural variant of Wagnerite
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Formula:
Mg2(PO4)F
Colour:
reddish yellow
Lustre:
Vitreous
Hardness:
5 - 6
Specific Gravity:
3.177 (Calculated)
Crystal System:
Monoclinic
A polytype of Wagnerite
The primary difference between the wagnerite-Ma5bc and wagnerite-Ma2bc (e.g., type locality) is ordering of the (F,OH) positions.
In general, none of the optical and physical properties listed in Table 1 can be used to distinguish wagnerite-Ma5bc from wagnerite-Ma2bc and magniotriplite because these properties depend much more on (Fe + Mn) content than on crystal structure (Fin’ko 1962, Propach 1976). X-ray diffraction is needed to identify magniotriplite and the wagnerite polytypes.
The primary difference between the wagnerite-Ma5bc and wagnerite-Ma2bc (e.g., type locality) is ordering of the (F,OH) positions.
In general, none of the optical and physical properties listed in Table 1 can be used to distinguish wagnerite-Ma5bc from wagnerite-Ma2bc and magniotriplite because these properties depend much more on (Fe + Mn) content than on crystal structure (Fin’ko 1962, Propach 1976). X-ray diffraction is needed to identify magniotriplite and the wagnerite polytypes.
Unique Identifiers
Mindat ID:
41188
Long-form identifier:
mindat:1:1:41188:6
Physical Properties of Wagnerite-Ma5bc
Vitreous
Colour:
Reddish yellow
Streak:
Pale yellow
Hardness:
5 - 6 on Mohs scale
Cleavage:
Poor/Indistinct
Two poor cleavages
Two poor cleavages
Density:
3.177 g/cm3 (Calculated)
Optical Data of Wagnerite-Ma5bc
Type:
Biaxial (+)
RI values:
nα = 1.571(2) nβ = 1.577(3) nγ = 1.591(2)
2V:
Measured: 30° (15), Calculated: 67°
Max. Birefringence:
δ = 0.020
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:
Dispersion is moderate, v > r
Pleochroism:
Visible
Comments:
X very pale yellow, Y and Z medium yellow
Chemistry of Wagnerite-Ma5bc
Mindat Formula:
Mg2(PO4)F
Element Weights:
Elements listed:
Crystallography of Wagnerite-Ma5bc
Crystal System:
Monoclinic
Class (H-M):
m - Domatic
Cell Parameters:
a = 9.645(2) Å, b = 31.659(6) Å, c = 11.914(2) Å
β = 108.26(3)°
β = 108.26(3)°
Ratio:
a:b:c = 0.305 : 1 : 0.376
Unit Cell V:
3454.76 ų
Z:
40
Comment:
Space group Ia (non-standard setting).
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 Wagnerite-Ma5bc
mindat.org URL:
https://www.mindat.org/min-41188.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Wagnerite-Ma5bc
Localities for Wagnerite-Ma5bc
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 | |
| Ren et al. (2003) |
