Medvedevite
A valid IMA mineral species
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Formula:
KMn2+2V2O6Cl · 2H2O
Colour:
bright red
Crystal System:
Monoclinic
Name:
The mineral has been named in honour of the Russian geologist and chemist Robert Alexandrovich Medvedev (1939–2005).
New structure type. Unique combination of elements (at the upload time).
Unique Identifiers
Mindat ID:
55755
Long-form identifier:
mindat:1:1:55755:9
IMA Classification of Medvedevite
Classification of Medvedevite
8.F0.
8 : PHOSPHATES, ARSENATES, VANADATES
F : Polyphosphates, Polyarsenates, [4]-Polyvanadates
0 :
8 : PHOSPHATES, ARSENATES, VANADATES
F : Polyphosphates, Polyarsenates, [4]-Polyvanadates
0 :
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 for Standard |
|---|---|---|
| Mvv | 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 Medvedevite
Transparency:
Transparent
Colour:
Bright red
Optical Data of Medvedevite
Type:
Biaxial (+)
RI values:
nα = 1.782(2) nβ = 1.786(2) nγ = 1.792(2)
2V:
Calculated: 41°
Max. Birefringence:
δ = 0.010
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:
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.
Chemistry of Medvedevite
Mindat Formula:
KMn2+2V2O6Cl · 2H2O
Element Weights:
Crystallography of Medvedevite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P21/b
Setting:
P21/c
Cell Parameters:
a = 7.1863(2) Å, b = 10.1147(3) Å, c = 12.7252(4) Å
β = 106.243(3)°
β = 106.243(3)°
Ratio:
a:b:c = 0.71 : 1 : 1.258
Unit Cell V:
888.04 ų (Calculated from Unit Cell)
Z:
4
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 7.79 Å | (100) |
| 5.70 Å | (11) |
| 4.75 Å | (14) |
| 3.89 Å | (29) |
| 3.25 Å | (53) |
| 3.05 Å | (19) |
| 2.958 Å | (79) |
| 2.850 Å | (33) |
Type Occurrence of Medvedevite
General Appearance of Type Material:
thin acicular crystals up to 0.15 mm.
Place of Conservation of Type Material:
collections of the Saint Petersburg
State University mineralogical museum, University Emb. 7/9, St. Petersburg 199034, Russia, catalogue number 1/19900
State University mineralogical museum, University Emb. 7/9, St. Petersburg 199034, Russia, catalogue number 1/19900
Geological Setting of Type Material:
formed during the 2012–2013 Tolbachik fissure eruption.
Associated Minerals at Type Locality:
Synonyms of Medvedevite
Other Language Names for Medvedevite
Dutch:Medvedeviet
German:Medvedevit
Related Minerals - Strunz-mindat Grouping
| 8.F0.05 | Kainotropite | Cu4Fe3+O2(V2O7)(VO4) |
Radioactivity
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 Medvedevite
mindat.org URL:
https://www.mindat.org/min-55755.html
Please feel free to link to this page.
Please feel free to link to this page.
Search Engines:
External Links:
Mineral Dealers:
References for Medvedevite
Reference List:
Miyawaki, Ritsuro, Hatert, Frédéric, Pasero, Marco, Mills, Stuart J. (2022) IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) – Newsletter 65. European Journal of Mineralogy, 34 (1) 143-148 doi:10.5194/ejm-34-143-2022
Shablinskii, Andrey P., Avdontceva, Margarita S., Vergasova, Lidiya P., Filatov, Stanislav K., Avdontseva, Evgenia Yu., Povolotskiy, Alexey V., Moskaleva, Svetlana V., Kargopoltsev, Anatoly A., Britvin, Sergey N., Shorets, Olga U. (2022) Medvedevite, KMn2+V5+2O6Cl⋅2H2O, a new fumarolic mineral from the Tolbachik fissure eruption 2012–2013, Kamchatka Peninsula, Russia. Mineralogical Magazine, 86 (3) 478-485 doi:10.1180/mgm.2022.38
Localities for Medvedevite
Showing 1 localities.
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.
Russia (TL) | |
| Miyawaki et al. (2022) +1 other reference |
