Nepskoeite
A valid IMA mineral species
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About Nepskoeite
Formula:
Mg4Cl(OH)7 · 6H2O
Colour:
Colourless with a bright yellow tint.
Lustre:
Pearly
Hardness:
1½ - 2
Specific Gravity:
1.76
Crystal System:
Orthorhombic
Name:
Named after the Nepskoye potash/salt deposit, the type locality.
This page provides mineralogical data about Nepskoeite.
Unique Identifiers
Mindat ID:
7189
Long-form identifier:
mindat:1:1:7189:1
GUID
(UUID V4):
(UUID V4):
3471e4e3-cfcc-464b-860b-3e10b7852b23
IMA Classification of Nepskoeite
Approved
First published:
1998
Classification of Nepskoeite
3.BD.20
3 : HALIDES
B : Simple halides, with H2O
D : Simple halides with H2O and additional OH
3 : HALIDES
B : Simple halides, with H2O
D : Simple halides with H2O and additional OH
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 |
---|---|---|
Nep | 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 Nepskoeite
Pearly
Transparency:
Translucent
Colour:
Colourless with a bright yellow tint.
Streak:
White
Hardness:
1½ - 2 on Mohs scale
Density:
1.76(2) g/cm3 (Measured) 1.756 g/cm3 (Calculated)
Optical Data of Nepskoeite
Type:
Biaxial (-)
RI values:
nα = 1.532(2) nβ = 1.562(2) nγ = 1.562(2)
2V:
Measured: 5°
Max Birefringence:
δ = 0.030
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
and does not take into account mineral colouration.
Surface Relief:
Low
Dispersion:
weak
Optical Extinction:
Straight extinction, negative elongation
Chemistry of Nepskoeite
Mindat Formula:
Mg4Cl(OH)7 · 6H2O
Elements listed:
Crystallography of Nepskoeite
Crystal System:
Orthorhombic
Cell Parameters:
a = 11.215(9) Å, b = 3.124(3) Å, c = 19.21(3) Å
Ratio:
a:b:c = 3.59 : 1 : 6.149
Unit Cell V:
673.04 ų (Calculated from Unit Cell)
Z:
2
Comment:
space group Pcmm, Pcm21 or Pc2m
X-Ray Powder Diffraction
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
11.41 Å | (29) |
9.78 Å | (46) |
9.60 Å | (38) |
4.25 Å | (20) |
3.498 Å | (100) |
Geological Environment
Paragenetic Mode(s):
Paragenetic Mode | Earliest Age (Ga) |
---|---|
Near-surface Processes | |
25 : Evaporites (prebiotic) |
Type Occurrence of Nepskoeite
General Appearance of Type Material:
Occurs as 0.5–1.5 mm spherulites consisting of 0.5–1.0 mm fibers.
Place of Conservation of Type Material:
A. E. Fersman Mineralogical Museum, Moscow, Russia.
Associated Minerals at Type Locality:
Reference:
Apollonov, V.N. (1998) Nepskoeite Mg4Cl(OH)7·6H2O — a new mineral from the Nepskoye potash salt deposit. Zapiski Vserossijskogo Mineralogicheskogo Obshchestva: 127(1): 41-46.
Synonyms of Nepskoeite
Other Language Names for Nepskoeite
German:Nepskoeit
Spanish:Nepskoeita
Related Minerals - Strunz-mindat Grouping
3.BD.05 | Cadwaladerite | Al5(H2O)3(OH)12 · n(Cl,H2O) |
3.BD.15 | Korshunovskite | Mg2Cl(OH)3 · 4H2O |
3.BD.25 | Koenenite | Na4Mg9Al4Cl12(OH)22 |
Other Information
IR Spectrum:
Bands at 3623, 3373, 1609, 1297, 1160 (weak), 733, and 591 cm–1.
Thermal Behaviour:
TG analysis: gradual weight loss (42.73 wt% at 900 °C)
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 Nepskoeite
mindat.org URL:
https://www.mindat.org/min-7189.html
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Please feel free to link to this page.
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References for Nepskoeite
Localities for Nepskoeite
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).
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.
All localities listed without proper references should be considered as questionable.
Russia (TL) | |
| Apollonov (1998) +1 other reference |
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Nepskoe K salt deposit, Nepa River basin, Lower Tunguska, Irkutsk Oblast, Russia