Dashkovaite
A valid IMA mineral species
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About Dashkovaite
Yekaterina Romanovna Vorontsova-Dashkova
Formula:
Mg(HCOO)2 · 2H2O
Colour:
White
Lustre:
Vitreous
Hardness:
1
Specific Gravity:
1.74 (Calculated)
Crystal System:
Monoclinic
Name:
Named in honor of Yekaterina Romanovna Vorontsova-Dashkova (Екатери́на Рома́новна Воронцо́ва-Да́шкова) (28 March (17 March) 1743 – 15 January (4 January) 1810), President of the Russian Academy of Sciences. She was the first woman in the world to head a national academy of sciences and helped found the Russian Academy.
Magnesium formate dihydrate.
Unique Identifiers
Mindat ID:
10175
Long-form identifier:
mindat:1:1:10175:8
IMA Classification of Dashkovaite
Approved
IMA Formula:
Mg(HCOO)1-2·2H2O
Approval year:
2000
First published:
2000
Classification of Dashkovaite
10.AA.10
10 : ORGANIC COMPOUNDS
A : Salts of organic acids
A : Formates, Acetates, etc.
10 : ORGANIC COMPOUNDS
A : Salts of organic acids
A : Formates, Acetates, etc.
Dana 7th ed.:
50.2.4.1
50.02.06.02
50 : ORGANIC COMPOUNDS
02 :
50 : ORGANIC COMPOUNDS
02 :
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 |
|---|---|---|
| Dkv | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Pronunciation of Dashkovaite
Pronunciation:
| Play | Recorded by | Country |
|---|---|---|
| Jolyon Ralph | United Kingdom |
Physical Properties of Dashkovaite
Vitreous
Transparency:
Transparent
Colour:
White
Streak:
White
Hardness:
1 on Mohs scale
Tenacity:
Sectile
Fracture:
Irregular/Uneven
Density:
1.74 g/cm3 (Calculated)
Optical Data of Dashkovaite
Type:
Biaxial (+)
RI values:
nα = 1.465 nβ = 1.486 nγ = 1.516
2V:
Calculated: 81°
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 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 (negative)
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:
r > v strong
Optical Extinction:
X = elongation.
Chemistry of Dashkovaite
Mindat Formula:
Mg(HCOO)2 · 2H2O
Element Weights:
Elements listed:
Crystallography of Dashkovaite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P21/b
Setting:
P21/c
Cell Parameters:
a = 8.64(1) Å, b = 7.15(1) Å, c = 9.38(1) Å
β = 98°
β = 98°
Ratio:
a:b:c = 1.208 : 1 : 1.312
Unit Cell V:
573.82 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Fibrous, in porous aggregates.
Comment:
Space group by analogy to synthetic.
Crystal Structure
Load
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Show
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Display Options
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
View
CIF File Best | x | y | z | a | b | c
CIF File Best | x | y | z | a | b | c
Rotation
Stop | Start
Stop | Start
Labels
Console Off | On | Grey | Yellow
Console Off | On | Grey | Yellow
Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
| ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
|---|---|---|---|---|---|---|---|
| 0014166 | Dashkovaite | Osaki K, Nakai Y, Watanabe T (1964) The crystal structure of magnesium formate dihydrate and manganous formate dihydrate Journal of the Physical Society of Japan 19 717-723 | 1964 | synthetic | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 3.40 Å | (100) |
| 4.90 Å | (90) |
| 4.64 Å | (80) |
| 3.68 Å | (80) |
| 4.30 Å | (70) |
| 5.45 Å | (40) |
| 4.56 Å | (40) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 3b: Earth’s earliest hydrosphere | >4.45 |
| 13 : Hadean serpentinization |
Type Occurrence of Dashkovaite
General Appearance of Type Material:
Veinlets 1 mm thick made up of fibers to 3 mm long.
Place of Conservation of Type Material:
A.E. Fersman Mineralogical Museum, Academy of Sciences, Moscow, Russia, 81597.
Geological Setting of Type Material:
Hydrothermal veinlets in serpentine in dolomitic marble.
Associated Minerals at Type Locality:
Synonyms of Dashkovaite
Other Language Names for Dashkovaite
Related Minerals - Strunz-mindat Grouping
| 10.AA. | Henrysunite | Na2(C2H3O3)2(H2O) |
| 10.AA.05 | Formicaite | Ca(HCOO)2 |
| 10.AA.20 | Acetamide | CH3CONH2 |
| 10.AA.25 | Calclacite | Ca(CH3COO)Cl · 5H2O |
| 10.AA.30 | Paceite | CaCu(CH3COO)4 · 6H2O |
| 10.AA.35 | Hoganite | Cu(CH3COO)2 · H2O |
| 10.AA.40 | Lianbinite | (NH4)(C2H3O3)(C2H4O3) |
| 10.AA.40 | Domitrovicite | Zn(C2H3O3)2 · 2H2O |
| 10.AA.40 | Puschridgeite | Mn(C2H3O3)2(H2O)2 |
| 10.AA.40 | Lazaraskeite | Cu(C2H3O3)2 |
| 10.AA.40 | Glecklerite | Na(C2H3O3) |
| 10.AA.40 | Jimkrieghite | Ca(C2H3O3)2 |
| 10.AA.40 | Stanevansite | Mg(C2H3O3)2 · 2H2O |
| 10.AA.40 | Rasmussenite | Ca(C2H3O3)2 · 3H2O |
| 10.AA.45 | Marchettiite | C5H7N5O3 |
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 Dashkovaite
mindat.org URL:
https://www.mindat.org/min-10175.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Dashkovaite
Reference List:
Mandarino, Joseph A. (2001) New minerals. The Canadian Mineralogist, 39 (5) 1473-1502 doi:10.2113/gscanmin.39.5.1473
Localities for Dashkovaite
Showing 2 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 | |
| |
| Chukanov et al. (2000) +1 other reference |
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Solongo B deposit, Ozernoe ore cluster, Yeravninsky District, Buryatia, Russia