Matveevite
A variety of Benyacarite
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Formula:
(H2O,K)2(Mn2+,Fe2+)2(Fe3+,Ti)2Ti(PO4)4(O,F)2 · 14H2O
Lustre:
Vitreous
Crystal System:
Orthorhombic
Name:
Named for K. K. Matveev (1875-1954).
A Mg-Al-bearing benyacarite.
Unique Identifiers
Mindat ID:
7171 (as Matveevite)
6823 (as Benyacarite)
6823 (as Benyacarite)
Long-form identifier:
mindat:1:1:7171:6 (as Matveevite)
mindat:1:1:6823:5 (as Benyacarite)
mindat:1:1:6823:5 (as Benyacarite)
IMA Classification of Matveevite
Discredited
Physical Properties of Matveevite
Vitreous
Optical Data of Matveevite
Type:
Biaxial (+)
RI values:
nα = 1.574 nβ = 1.58 nγ = 1.618
Max. Birefringence:
δ = 0.044
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. 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 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. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
Moderate (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.
No measured or calculated 2V is on file for this mineral, so the value used here (44°) is estimated from its recorded refractive indices and optic sign, not from a direct 2V measurement.
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.
No measured or calculated 2V is on file for this mineral, so the value used here (44°) is estimated from its recorded refractive indices and optic sign, not from a direct 2V measurement.
Dispersion:
none
Chemistry of Matveevite
Mindat Formula:
(H2O,K)2(Mn2+,Fe2+)2(Fe3+,Ti)2Ti(PO4)4(O,F)2 · 14H2O
Element Weights:
Crystallography of Matveevite
Crystal System:
Orthorhombic
Other Language Names for Matveevite
German:Matveevit
Spanish:Matveevita
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 Matveevite
mindat.org URL:
https://www.mindat.org/min-7171.html
Please feel free to link to this page.
Please feel free to link to this page.
Search Engines:
Mineral Dealers:
References for Matveevite
Reference List:
Jambor, L., Puziewicz, Jacek (1993) New Mineral Names. American Mineralogist, 78 (3-4) 450-455 p.451
Demartin, F., Gay, H. D., Gramaccioli, C. M., Pilati, T. (1997) Benyacarite, a new titanium-bearing phosphate mineral species from Cerro Blanco, Argentina. The Canadian Mineralogist, 35 (3) 707-712
Localities for Matveevite
Showing 1 localities.
ⓘ - 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).
Struck out - Mineral was erroneously reported from this locality.
Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).
All localities listed without proper references should be considered as questionable.
- 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.
Russia | |
| Kydryashova et al. (1991) |
