Packratite
A valid IMA mineral species
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About Packratite
Formula:
Ca11(As3+V5+10V4+2As5+6O51)2 · 83H2O
Colour:
Very dark greenish blue
Lustre:
Vitreous
Hardness:
2
Specific Gravity:
2.36
Crystal System:
Triclinic
Member of:
Name:
Named for the Packrat mine, the type locality.
New structure type.
Unique Identifiers
Mindat ID:
46228
Long-form identifier:
mindat:1:1:46228:8
IMA Classification of Packratite
Approved
IMA Formula:
Ca11(As3+V5+10V4+2As5+6O51)2·83H2O
Approval year:
2014
First published:
2016
Type description reference:
Classification of Packratite
8.FD.10
8 : PHOSPHATES, ARSENATES, VANADATES
F : Polyphosphates, Polyarsenates, [4]-Polyvanadates
D : Polyphosphates, etc., with OH and H2O
8 : PHOSPHATES, ARSENATES, VANADATES
F : Polyphosphates, Polyarsenates, [4]-Polyvanadates
D : Polyphosphates, etc., with OH and H2O
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 |
|---|---|---|
| Pkt | 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 Packratite
Vitreous
Transparency:
Translucent
Colour:
Very dark greenish blue
Streak:
Grayish blue
Hardness:
2 on Mohs scale
Tenacity:
Brittle
Cleavage:
Imperfect/Fair
{001}, {110}, and {1–10} fair
{001}, {110}, and {1–10} fair
Density:
2.36(2) g/cm3 (Measured) 2.351 g/cm3 (Calculated)
Optical Data of Packratite
Type:
Biaxial (-)
RI values:
nα = 1.625 nβ = 1.628(2) nγ = 1.629(2)
2V:
Measured: 60.7° (4)
Max. Birefringence:
δ = 0.004
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:
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
Pleochroism:
Non-pleochroic
Comments:
non-pleochroic dark blue
Chemistry of Packratite
Mindat Formula:
Ca11(As3+V5+10V4+2As5+6O51)2 · 83H2O
Element Weights:
Crystallography of Packratite
Crystal System:
Triclinic
Class (H-M):
1 - Pinacoidal
Space Group:
P1
Setting:
P1
Cell Parameters:
a = 18.0572(4) Å, b = 19.4126(4) Å, c = 24.0586(17) Å
α = 87.364(6)°, β = 86.266(6)°, γ = 79.267(6)°
α = 87.364(6)°, β = 86.266(6)°, γ = 79.267(6)°
Ratio:
a:b:c = 0.93 : 1 : 1.239
Unit Cell V:
8263.4 ų
Z:
2
Morphology:
Flattened on {110} and elongated on [001]
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) |
|---|---|---|---|---|---|---|---|
| M12048 | Packratite | Kampf, A. R., Hughes, J. M., P. Nash, B., & Marty, J. (2016) Vanarsite, packratite, morrisonite, and gatewayite: four new minerals containing the [As3+V4+,5+12As5+6O51] heteropolyanion, a novel polyoxometalate cluster. The Canadian Mineralogist, 54 (1) 145-162 doi:10.3749/canmin.1500062 | 2016 | Packrat Mine, Colorado, USA | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 14.50 Å | (49) |
| 12.13 Å | (49) |
| 10.53 Å | (100) |
| 7.45 Å | (20) |
| 6.61 Å | (16) |
| 2.939 Å | (22) |
| 2.846 Å | (19) |
| 2.732 Å | (22) |
Reference:
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| 47d : [Arsenates, antimonates, selenates, bismuthinates] | |
| 47e : [Vanadates, chromates, manganates] |
Type Occurrence of Packratite
General Appearance of Type Material:
Very dark blue to greenish-blue blades up to about 1 mm long, striated lengthwise, and grow in sub-parallel and divergent intergrowths. Also as pearly green, botryoidal aggregates.
Place of Conservation of Type Material:
Type material is deposited in the collections of the Natural History Museum of Los Angeles County, California, USA, catalogue numbers 64513 and 64514
Associated Minerals at Type Locality:
Reference:
Synonyms of Packratite
Other Language Names for Packratite
Dutch:Packratiet
German:Packratit
Relationship of Packratite to other Species
Member of:
Other Members of Vanarsite Group:
| Gatewayite | Ca6(As3+V4+3 V5+9As5+6O51) · 31H2O | Mon. 2 : P21 |
| Lumsdenite | NaCa3Mg2(As3+V4+2V5+10As5+6O51) · 45H2O | Tric. 1 : P1 |
| Morrisonite | Ca11(As3+V4+2V5+10As5+6O51)2 · 78H2O | Mon. 2/m : P21/c |
| Vanarsite | NaCa12(As3+V5+8.5V4+3.5As5+6O51)2 · 78H2O | Mon. 2/m : P21/c |
Common Associates
Associations Based on Photo Data:
| 1 photo of Packratite associated with Pharmacolite | Ca(HAsO4) · 2H2O |
| 1 photo of Packratite associated with Fulbrightite | Ca(V4+O)2(As5+O4)2 · 4H2O |
Related Minerals - Strunz-mindat Grouping
| 8.FD.05 | Volborthite | Cu3(V2O7)(OH)2 · 2H2O |
| 8.FD.05 | Martyite | Zn3(V2O7)(OH)2 · 2H2O |
| 8.FD.05 | Karpenkoite | Co3(V2O7)(OH)2 · 2H2O |
| 8.FD.10 | Vanarsite | NaCa12(As3+V5+8.5V4+3.5As5+6O51)2 · 78H2O |
| 8.FD.10 | Bicapite | [KNa2Mg2(H2O)25][H2PV5+12O40(V5+O)2] |
| 8.FD.10 | Morrisonite | Ca11(As3+V4+2V5+10As5+6O51)2 · 78H2O |
| 8.FD.10 | Lumsdenite | NaCa3Mg2(As3+V4+2V5+10As5+6O51) · 45H2O |
| 8.FD.10 | Gatewayite | Ca6(As3+V4+3 V5+9As5+6O51) · 31H2O |
| 8.FD.10 | Kegginite | Pb3Ca3[AsV12O40(VO)] · 20H2O |
| 8.FD.15 | Chinchorroite | Na2Mg5(As2O7)2(AsO3OH)2(H2O)10 |
Fluorescence of Packratite
None
Other Information
Notes:
Insoluble in room-temperature H2O; easily soluble in room-temperature dilute HCl.
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 Packratite
mindat.org URL:
https://www.mindat.org/min-46228.html
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Please feel free to link to this page.
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References for Packratite
Reference List:
Williams, P. A., Hatert, F., Pasero, M., Mills, S. J. (2014) IMA Commission on New Minerals, Nomenclature and Classification (CNMNC), CNMNC Newsletter No. 22. Mineralogical Magazine, 78 (5) 1241-1248 doi:10.1180/minmag.2014.078.5.10
Localities for Packratite
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.
USA (TL) | |
| Natural History Museum of Los Angeles ... +2 other references |
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Mesa County, Colorado, USA