Pascoite
A valid IMA mineral species - grandfathered
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About Pascoite
Flag of Dept. of Pasco, Peru
Formula:
Ca2Ca(V10O28) · 17H2O
Colour:
Dark red-orange to yellow-orange; dirty yellow (upon partial dehydration).
Lustre:
Sub-Adamantine, Vitreous
Hardness:
2½
Specific Gravity:
2.455
Crystal System:
Monoclinic
Member of:
Name:
Named after the province/department of Pasco, Peru. The type locality is in the department.
Type Locality:
See also the closely related magnesiopascoite and hydropascoite, the latter being the higher hydrated equivalent.
A secondary mineral occurring as a leachate of near-surface vanadium oxides by ground waters and as efflorescences in mine tunnels.
A secondary mineral occurring as a leachate of near-surface vanadium oxides by ground waters and as efflorescences in mine tunnels.
Unique Identifiers
Mindat ID:
3130
Long-form identifier:
mindat:1:1:3130:7
Similar Names
| Písekite-(Y) | A valid IMA mineral species - grandfathered - questionable | (Y,As,Ca,Fe,U)(Nb,Ti,Ta)O4 |
Classification of Pascoite
The Decavanadate Cluster
The decavanadate cluster found in pascoite. The same cluster is known in a number of other secondary vanadium minerals including, for example, magnesiopascoite, wernerbaurite, and huemulite.
IMA Classification of Pascoite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
[Ca3(H2O)17]V5+10O28
First published:
1914
Type description reference:
4.HC.05
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
47.2.1.1
47 : VANADIUM OXYSALTS
2 : Anhydrous Vanadium Oxysalts Containing Hydroxyl or Halogen
47 : VANADIUM OXYSALTS
2 : Anhydrous Vanadium Oxysalts Containing Hydroxyl or Halogen
21.2.8
21 : Vanadates (and vanadates with arsenate or phosphate)
2 : Vanadates of Mg, Ca, Sr or Ba
21 : Vanadates (and vanadates with arsenate or phosphate)
2 : Vanadates of Mg, Ca, Sr or Ba
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 |
|---|---|---|
| Pas | 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 Pascoite
Sub-Adamantine, Vitreous
Transparency:
Translucent
Colour:
Dark red-orange to yellow-orange; dirty yellow (upon partial dehydration).
Streak:
Cadmium-yellow
Hardness:
2½ on Mohs scale
Cleavage:
Distinct/Good
On {010}, distinct
On {010}, distinct
Fracture:
Conchoidal
Density:
2.455 g/cm3 (Measured) 2.465 g/cm3 (Calculated)
Optical Data of Pascoite
Type:
Biaxial (-)
RI values:
nα = 1.775 nβ = 1.815 nγ = 1.825
2V:
Measured: 50° to 56°, Calculated: 52°
Max. Birefringence:
δ = 0.050
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.
Dispersion:
r < v strong
Pleochroism:
Visible
Comments:
X = Light cadmium-yellow
Y = Cadmium yellow
Z = Orange
Y = Cadmium yellow
Z = Orange
Chemistry of Pascoite
Mindat Formula:
Ca2Ca(V10O28) · 17H2O
Element Weights:
Elements listed:
Crystallography of Pascoite
Crystal System:
Monoclinic
Class (H-M):
2 - Sphenoidal
Space Group:
B2
Cell Parameters:
a = 16.834 Å, b = 10.156 Å, c = 10.921 Å
β = 93.13°
β = 93.13°
Ratio:
a:b:c = 1.658 : 1 : 1.075
Unit Cell V:
1,864.34 ų (Calculated from Unit Cell)
Z:
2
Morphology:
Crystals minute, lath-like with oblique terminations; {110} striated [001], and {111} striated [101]; granular crusts.
Crystal Structure
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Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
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CIF File Best | x | y | z | a | b | c
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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) |
|---|---|---|---|---|---|---|---|
| 0006048 | Pascoite | Hughes J M, Schindler M, Francis C A (2005) The C2/m disordered structure of pascoite, Ca3[V10O28]*17H2O: Bonding between structural units and interstitial complexes in compounds containing the [V10O28]6- decavanadanate polyanion The Canadian Mineralogist 43 1379-1386 |  | 2005 | Minasragra, Peru | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 8.8 Å | (6) |
| 7.3 Å | (7) |
| 5.5 Å | (10) |
| 5.1 Å | (8) |
| 4.67 Å | (10) |
| 4.45 Å | (6) |
| 3.01 Å | (7) |
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 |
Geological Setting:
Near surface leaching of vanadium oxides by ground waters; post-mining efflorescences on mine tunnels.
Type Occurrence of Pascoite
General Appearance of Type Material:
Efflorescences on mine tunnels
Place of Conservation of Type Material:
Harvard University, Cambridge, Massachusetts, USA: #1017012. U.S. National Museum of Natural History, Washington, D.C., USA: #87662, 93297.
Other Language Names for Pascoite
Relationship of Pascoite to other Species
Member of:
Other Members of Pascoite Family:
| Ammoniolasalite | [(NH4)2Mg2(H2O)20] [V10O28] | Mon. 2/m : B2/b |
| Bluestreakite | K4Mg2(V4+2V5+8O28) · 14H2O | Mon. 2/m |
| Burroite | Ca2(NH4)2(V10O28) · 15H2O | Tric. 1 : P1 |
| 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) | Mon. |
| Flatimerite | [Al13(OH)24(H2O)24][V5+9V4+O28] · [(SO4)4(H2O)24] | Tric. 1 : P1 |
| Gunterite | Na4Ca(V10O28) · 20H2O | Mon. 2/m : B2/m |
| Huemulite | Na4Mg(V10O28) · 24H2O | Tric. |
| Hughesite | Na3Al(V10O28) · 22H2O | Tric. 1 : P1 |
| Hummerite | K2Mg2(V10O28) · 16H2O | Tric. 1 : P1 |
| Hydropascoite | Ca3(V10O28) · 24H2O | Tric. 1 : P1 |
| Kokinosite | Na2Ca2(V10O28) · 24H2O | Tric. 1 : P1 |
| Lasalite | Na2Mg2(V10O28) · 20H2O | Mon. 2/m : B2/b |
| Magnesiopascoite | Ca2Mg(V10O28) · 16H2O | Mon. 2/m : B2/m |
| Nashite | Na3Ca2[(V5+9V4+)O28] · 24H2O | Mon. 2/m : P21/m |
| Okieite | Mg3[V10O28] · 28H2O | Tric. 1 : P1 |
| Postite | Mg(H2O)6Al2(OH)2(H2O)8(V10O28) · 13H2O | Orth. mmm(2/m2/m2/m) : Pccn |
| Protocaseyite | [Al4(OH)6(H2O)12][V10O28] · 8H2O | Tric. 1 : P1 |
| Rakovanite | (NH4)3Na3(V10O28) · 12H2O | Mon. 2/m |
| Schindlerite | {(NH4)4Na2(H2O)10}{V10O28} | Tric. 1 : P1 |
| Trebiskyite | Na3Mg2[TiV9O28] · 22H2O | Mon. 2/m : P21/b |
| Wernerbaurite | {(NH4)2[Ca2(H2O)14](H2O)2}{V10O28} | Tric. 1 : P1 |
Common Associates
Associations Based on Photo Data:
| 13 photos of Pascoite associated with Corvusite | (Na,K,Ca,Mg)2(V5+,V4+,Fe2+)8O20 · 6-10H2O |
| 11 photos of Pascoite associated with Metarossite | Ca(V2O6) · 2H2O |
| 10 photos of Pascoite associated with Lasalite | Na2Mg2(V10O28) · 20H2O |
| 9 photos of Pascoite associated with Montroseite | (V3+,Fe3+)O(OH) |
| 8 photos of Pascoite associated with Rossite | Ca(VO3)2 · 4H2O |
| 8 photos of Pascoite associated with Huemulite | Na4Mg(V10O28) · 24H2O |
| 5 photos of Pascoite associated with Hewettite | CaV6O16 · 9H2O |
| 5 photos of Pascoite associated with Gypsum | CaSO4 · 2H2O |
| 4 photos of Pascoite associated with 'Sandstone' | |
| 4 photos of Pascoite associated with Sherwoodite | Ca5.5(AlV4+V5+12O39) · 28H2O |
Related Minerals - Strunz-mindat Grouping
| 4.HC. | Protocaseyite | [Al4(OH)6(H2O)12][V10O28] · 8H2O |
| 4.HC. | Ammoniolasalite | [(NH4)2Mg2(H2O)20] [V10O28] |
| 4.HC. | Beckettite | Ca2V6Al6O20 |
| 4.HC. | Flatimerite | [Al13(OH)24(H2O)24][V5+9V4+O28] · [(SO4)4(H2O)24] |
| 4.HC.05 | Hydropascoite | Ca3(V10O28) · 24H2O |
| 4.HC.05 | Lasalite | Na2Mg2(V10O28) · 20H2O |
| 4.HC.05 | Hughesite | Na3Al(V10O28) · 22H2O |
| 4.HC.05 | Magnesiopascoite | Ca2Mg(V10O28) · 16H2O |
| 4.HC.05 | Rakovanite | (NH4)3Na3(V10O28) · 12H2O |
| 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.55 | Postite | Mg(H2O)6Al2(OH)2(H2O)8(V10O28) · 13H2O |
| 4.HC.60 | Schindlerite | {(NH4)4Na2(H2O)10}{V10O28} |
Other Information
Notes:
Soluble in water.
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 Pascoite
mindat.org URL:
https://www.mindat.org/min-3130.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Pascoite
Reference List:
Frost, Ray L, Erickson, Kristy L, Weier, Matt L (2004) Hydrogen bonding in selected vanadates: a Raman and infrared spectroscopy study. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 60 (10) 2419-2423 doi:10.1016/j.saa.2003.12.017
Hughes, J. M., Schindler, M., Francis, C. A. (2005) The C2/m disordered structure of pascoite, Ca3[V10O28]·17H2O: bonding between structural units and interstitial complexes in compounds containing the [V10O28]6- decavanadanate polyanion. The Canadian Mineralogist, 43 (4) 1379-1386 doi:10.2113/gscanmin.43.4.1379
Locock, A. J., Piilonen, P. C., Ercit, T. S., Rowe, R., Kolitsch, U. (2006) New mineral names. American Mineralogist, 91 (4) 710-715 doi:10.2138/am.2006.463
Reddy, G. Udayabhaskara, Reddy, R. Ramasubba, Reddy, S. Lakshmi, Frost, Ray L., Endo, Tamio (2011) Spectroscopic and structural characterization of pascoite. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 79 (5) 1402-1405 doi:10.1016/j.saa.2011.04.075
Localities for Pascoite
Showing 100 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.
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Burro Mine, San Miguel County, Colorado, USA