Postite
A valid IMA mineral species
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About Postite
Formula:
Mg(H2O)6Al2(OH)2(H2O)8(V10O28) · 13H2O
Colour:
golden yellow
Lustre:
Sub-Adamantine
Hardness:
2
Specific Gravity:
2.226 (Calculated)
Crystal System:
Orthorhombic
Name:
Named in honor of Dr. Jeffrey E. Post (b.1954), mineralogist and curator of the Smithsonian Institution mineral and gem collections.
This page provides mineralogical data about Postite.
Unique Identifiers
Mindat ID:
42268
Long-form identifier:
mindat:1:1:42268:8
GUID
(UUID V4):
(UUID V4):
4e7a766c-ce8f-42b3-afc5-3b1fc1b7df84
IMA Classification of Postite
Approved
IMA Formula:
Mg(H2O)6Al2(OH)2(H2O)8(V10O28) · 13H2O
Approval year:
2011
First published:
2012
Classification of Postite
4.HC.55
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
H : V[5,6] Vanadates
C : [6]-Sorovanadates
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
H : V[5,6] Vanadates
C : [6]-Sorovanadates
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 |
---|---|---|
Pos | 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 Postite
Sub-Adamantine
Transparency:
Transparent
Colour:
golden yellow
Streak:
yellow
Hardness:
2 on Mohs scale
Tenacity:
Brittle
Cleavage:
Perfect
one good cleavage on {001} and at least two perfect cleavages parallel to [001], possibly on {100} and {010}
one good cleavage on {001} and at least two perfect cleavages parallel to [001], possibly on {100} and {010}
Parting:
none
Fracture:
Splintery
Density:
2.226 g/cm3 (Calculated)
Comment:
density of postite could not be measured because the mineral dissolves in an aqueous sodium polytungstate solution
Optical Data of Postite
Type:
Biaxial (+)
RI values:
nα = 1.727(3) nβ = 1.733(3) nγ = 1.745(3)
2V:
Calculated: 71°
Max Birefringence:
δ = 0.018
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:
High
Dispersion:
not observed
Pleochroism:
Non-pleochroic
Chemistry of Postite
Mindat Formula:
Mg(H2O)6Al2(OH)2(H2O)8(V10O28) · 13H2O
Crystallography of Postite
Crystal System:
Orthorhombic
Class (H-M):
mmm (2/m 2/m 2/m) - Dipyramidal
Space Group:
Pccn
Setting:
Pccn
Cell Parameters:
a = 16.3357(6) Å, b = 24.2434(17) Å, c = 11.7343(4) Å
Ratio:
a:b:c = 0.674 : 1 : 0.484
Unit Cell V:
4,647.17 ų (Calculated from Unit Cell)
Z:
4
Crystal Structure
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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) |
---|---|---|---|---|---|---|---|
0019040 | Postite | Kampf A R, Hughes J M, Marty J, Nash B (2012) Postite, Mg(H2O)6Al2(OH)2(H2O)8(V10O28)*13H2O, a new mineral species from the La Sal Mining District, Utah: Crystal structure and descriptive mineralogy The Canadian Mineralogist 50 45-53 | 2012 | La Sal Mining District, Utah, USA | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
8.937 Å | (100) |
12.190 Å | (90) |
3.771 Å | (24) |
8.248 Å | (22) |
Geological Environment
Paragenetic Mode(s):
Paragenetic Mode | Earliest Age (Ga) |
---|---|
Stage 7: Great Oxidation Event | <2.4 |
47a : [Near-surface hydration of prior minerals] | |
47e : [Vanadates, chromates, manganates] | |
Stage 10b: Anthropogenic minerals | <10 Ka |
55 : Anthropogenic mine minerals |
Type Occurrence of Postite
Co-Type Localities:
General Appearance of Type Material:
very thin, needle-like prisms with pyramidal terminations; some needles are slightly curved. Crystals generally occur in parallel bundles and grow in divergent and “jackstraw” masses. Individual crystals are up to 1 mm long and 50 µm in diameter.
Place of Conservation of Type Material:
Natural History Museum of Los Angeles County under catalogue numbers 63564 (Vanadium Queen mine) and 63563 (Blue Cap mine).
Geological Setting of Type Material:
forms from the oxidation of montroseite-corvusite assemblages in a moist environment.
Associated Minerals at Type Locality:
Reference:
Kampf, A.R., Hughes, J.M., Marty, J., Nash, B. (2012) Postite, Mg(H2O)6Al2(OH)2(H2O)8(V10O28)∙13H2O, a new mineral species from the La Sal mining district, Utah: crystal structure and descriptive mineralogy. The Canadian Mineralogist: 50(1): 45-53.
Synonyms of Postite
Common Associates
Associated Minerals Based on Photo Data:
2 photos of Postite associated with Montroseite | (V3+,Fe3+)O(OH) |
1 photo of Postite associated with Corvusite | (Na,K,Ca,Mg)2(V5+,V4+,Fe2+)8O20 · 6-10H2O |
Related Minerals - Strunz-mindat Grouping
4.HC. | Beckettite | Ca2V6Al6O20 |
4.HC. | Ammoniolasalite | (NH4)2Mg2(H2O)20] [V10O28] |
4.HC. | Protocaseyite | [Al4(OH)6(H2O)12][V10O28] · 8H2O |
4.HC.05 | Pascoite | Ca2Ca(V10O28) · 17H2O |
4.HC.05 | Lasalite | Na2Mg2(V10O28) · 20H2O |
4.HC.05 | Magnesiopascoite | Ca2Mg(V10O28) · 16H2O |
4.HC.05 | Rakovanite | (NH4)3Na3(V10O28) · 12H2O |
4.HC.05 | Hughesite | Na3Al(V10O28) · 22H2O |
4.HC.05 | Hydropascoite | Ca3(V10O28) · 24H2O |
4.HC.10 | Hummerite | K2Mg2(V10O28) · 16H2O |
4.HC.15 | Sherwoodite | Ca5.5(AlV4+V5+12O39) · 28H2O |
4.HC.20 | Bluestreakite | K4Mg2(V4+2V5+8O28) · 14H2O |
4.HC.25 | Wernerbaurite | {(NH4)2[Ca2(H2O)14](H2O)2}{V10O28} |
4.HC.25 | Burroite | Ca2(NH4)2(V10O28) · 15H2O |
4.HC.30 | Caseyite | [(V5+O2)Al10-x(OH)20-2x(H2O)18-2x]2[H2V4+V5+9O28][V5+10O28]2(Na,K,Ca)2-y(SO4)2-z · (60+8x+y+4z)H2O (x = 0-2.5; y = 0-2; z = 0-2) |
4.HC.35 | Gunterite | Na4Ca(V10O28) · 20H2O |
4.HC.40 | Kokinosite | Na2Ca2(V10O28) · 24H2O |
4.HC.45 | Nashite | Na3Ca2[(V5+9V4+)O28] · 24H2O |
4.HC.50 | Okieite | Mg3[V10O28] · 28H2O |
4.HC.60 | Schindlerite | {(NH4)4Na2(H2O)10}{V10O28} |
Fluorescence of Postite
none
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 Postite
mindat.org URL:
https://www.mindat.org/min-42268.html
Please feel free to link to this page.
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References for Postite
Reference List:
Kampf, A. R., Hughes, J. M., Marty, J., Nash, B. (2012) Postite, Mg(H2O)6Al2(OH)2(H2O)8(V10O28)·13H2O, a new mineral species from the La Sal District, Utah: Crystal structure and descriptive mineralogy. The Canadian Mineralogist, 50 (1) 45-53 doi:10.3749/canmin.50.1.45
Localities for Postite
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.
USA | |
| Kampf et al. (2017) |
| Collected by and in the collection of ... |
| Collected By Chuck Adan |
| Williams et al. (2011) +1 other reference |
| Williams et al. (2011) +1 other reference |
| Joe Marty Collection |
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Effie F. Mine, Polar Mesa, Gateway Mining District, Grand County, Utah, USA