Haiweeite
A valid IMA mineral species
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About Haiweeite
Formula:
Ca(UO2)2[Si5O12(OH)2] · 6H2O
Colour:
Pale yellow, greenish-yellow
Lustre:
Pearly
Hardness:
3½
Specific Gravity:
3.35
Crystal System:
Orthorhombic
Name:
Named by T.C. McBurney and Joseph Murdoch in 1959 for the Haiwee Reservoir, California, located near the type locality.
Type Locality:
This page provides mineralogical data about Haiweeite.
Unique Identifiers
Mindat ID:
1802
Long-form identifier:
mindat:1:1:1802:5
Similar Names
IMA Classification of Haiweeite
Classification of Haiweeite
9.AK.25
9 : SILICATES (Germanates)
A : Nesosilicates
K : Uranyl neso- and polysilicates
9 : SILICATES (Germanates)
A : Nesosilicates
K : Uranyl neso- and polysilicates
53.3.2.2
53 : NESOSILICATES Insular SiO4 Groups and Other Anions or Complex Cations
3 : Insular SiO4 Groups and Other Anions of Complex Cations with (UO2)
53 : NESOSILICATES Insular SiO4 Groups and Other Anions or Complex Cations
3 : Insular SiO4 Groups and Other Anions of Complex Cations with (UO2)
14.16.12
14 : Silicates not Containing Aluminum
16 : Silicates of U
14 : Silicates not Containing Aluminum
16 : Silicates of U
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 |
|---|---|---|
| Hwe | 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 Haiweeite
Pearly
Transparency:
Translucent
Colour:
Pale yellow, greenish-yellow
Streak:
White
Hardness:
3½ on Mohs scale
Cleavage:
Distinct/Good
On {100}
On {100}
Density:
3.35 g/cm3 (Measured) 4.93 g/cm3 (Calculated)
Optical Data of Haiweeite
Type:
Biaxial (-)
RI values:
nα = 1.56 - 1.571 nβ = 1.575 - 1.58 nγ = 1.578 - 1.582
2V:
Measured: 15° , Calculated: 46° to 50°
Max. Birefringence:
δ = 0.011 - 0.018
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 (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
Comments:
Y = pale yellow; Z = colorless. Y = b.
Chemistry of Haiweeite
Mindat Formula:
Ca(UO2)2[Si5O12(OH)2] · 6H2O
Element Weights:
Crystallography of Haiweeite
Crystal System:
Orthorhombic
Class (H-M):
mmm(2/m2/m2/m) - Dipyramidal
Space Group:
Pbcn
Setting:
Pbcn
Cell Parameters:
a = 18.3000(5) Å, b = 14.2331(3) Å, c = 17.9192(5) Å
Ratio:
a:b:c = 1.286 : 1 : 1.259
Unit Cell V:
4,667.34 ų (Calculated from Unit Cell)
Z:
8
Comment:
Crystal from Teofilo Otoni, Minas Gerais, Brazil
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
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Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Display Options
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View
CIF File Best | x | y | z | a | b | c
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Rotation
Stop | Start
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Labels
Console Off | On | Grey | Yellow
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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) |
|---|---|---|---|---|---|---|---|
| 0019934 | Haiweeite | Plasil J, Fejfarova K, Cejka J, Dusek M, Skoda R, Sejkora J (2013) Revision of the crystal structure and chemical formula of haiweeite, Ca(UO2)2(Si5O12)(OH)2*6H2O American Mineralogist 98 718-723 | 2013 | Teofilo Otoni, Minas Gerais, Brazil | 0 | 293 | |
| 0005732 | Haiweeite | Burns P C (2001) A new uranyl silicate sheet in the structure of haiweeite and comparison to other uranyl silicates The Canadian Mineralogist 39 1153-1160 |  | 2001 | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 9.14 Å | (100) |
| 7.05 Å | (40) |
| 4.56 Å | (60) |
| 4.42 Å | (60) |
| 3.54 Å | (40) |
| 3.19 Å | (50) |
| 3.11 Å | (50) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Near-surface Processes | |
| 22 : Hydration and low-? subsurface aqueous alteration (see also #23) | |
| 25 : Evaporites (prebiotic) |
Type Occurrence of Haiweeite
General Appearance of Type Material:
Spherulitic aggregates, or single flakelike grains, on fracture surfaces in granite.
Synonyms of Haiweeite
Other Language Names for Haiweeite
Common Associates
Associations Based on Photo Data:
| 63 photos of Haiweeite associated with Uranophane | Ca(UO2)2(SiO3OH)2 · 5H2O |
| 43 photos of Haiweeite associated with Fluorite | CaF2 |
| 20 photos of Haiweeite associated with Gypsum | CaSO4 · 2H2O |
| 11 photos of Haiweeite associated with Calcite | CaCO3 |
| 11 photos of Haiweeite associated with Opal | SiO2 · nH2O |
| 10 photos of Haiweeite associated with Parauranophane | Ca(UO2)2(SiO3OH)2 · 5H2O |
| 8 photos of Haiweeite associated with Phosphuranylite | KCa(H3O)3(UO2)7(PO4)4O4 · 8H2O |
| 7 photos of Haiweeite associated with Albite | Na(AlSi3O8) |
| 4 photos of Haiweeite associated with Quartz | SiO2 |
| 3 photos of Haiweeite associated with 'Selenite' | CaSO4 · 2H2O |
Related Minerals - Strunz-mindat Grouping
| 9.AK. | 'Orlite' | Pb3(UO2)3(Si2O7)2 · 6H2O |
| 9.AK.05 | Soddyite | (UO2)2SiO4 · 2H2O |
| 9.AK.10 | Sklodowskite | Mg(UO2)2(SiO3OH)2 · 6H2O |
| 9.AK.10 | Cuprosklodowskite | Cu(UO2)2(SiO3OH)2 · 6H2O |
| 9.AK.10 | Oursinite | Co(UO2)2(SiO3OH)2 · 6H2O |
| 9.AK.15 | Parauranophane | Ca(UO2)2(SiO3OH)2 · 5H2O |
| 9.AK.15 | Uranophane | Ca(UO2)2(SiO3OH)2 · 5H2O |
| 9.AK.15 | Natroboltwoodite | Na(UO2)(SiO3OH) · H2O |
| 9.AK.15 | Kasolite | Pb(UO2)(SiO4) · H2O |
| 9.AK.15 | Boltwoodite | (K,Na)(UO2)(SiO3OH) · 1.5H2O |
| 9.AK.20 | Swamboite-(Nd) | Nd0.333[(UO2)(SiO3OH)](H2O)~2.5 |
| 9.AK.25 | Metahaiweeite | Ca(UO2)2Si6O15 · nH2O |
| 9.AK.30 | Weeksite | K2(UO2)2(Si5O13) · 4H2O |
| 9.AK.30 | Coutinhoite | ThxBa(1-2x)(UO2)2Si5O13 · (H2O)1+y (0 < x < 0.5 and 0 < y < (2+x)) |
| 9.AK.30 | Barronite | (◻0.5Ba0.5)(UO2)2Si5O12(OH) · 2H2O |
| 9.AK.35 | Magnioursilite | Mg4(UO2)4(Si2O5)5(OH)6 · 20H2O |
| 9.AK.35 | Calcioursilite | Ca4(UO2)4(Si2O5)5(OH)6 · 15H2O |
| 9.AK.40 | Uranosilite | UO3 · 7SiO2 |
Radioactivity
Radioactivity:
| Element | % Content | Activity (Bq/kg) | Radiation Type |
|---|---|---|---|
| Uranium (U) | 45.1385% | 11,284,625 | α, β, γ |
| Thorium (Th) | 0.0000% | 0 | α, β, γ |
| Potassium (K) | 0.0000% | 0 | β, γ |
For comparison:
- Banana: ~15 Bq per fruit
- Granite: 1,000–3,000 Bq/kg
- EU exemption limit: 10,000 Bq/kg
Note: Risk is shown relative to daily recommended maximum exposure to non-background radiation of 1000 µSv/year. Note that natural background radiation averages around 2400 µSv/year so in reality these risks are probably extremely overstated! With infrequent handling and safe storage natural radioactive minerals do not usually pose much risk.
Interactive Simulator:
Note: The mass selector refers to the mass of radioactive mineral present, not the full specimen, also be aware that the matrix may also be radioactive, possibly more radioactive than this mineral!
Activity: –
| Distance | Dose rate | Risk |
|---|---|---|
| 1 cm | ||
| 10 cm | ||
| 1 m |
The external dose rate (D) from a radioactive mineral is estimated by summing the gamma radiation contributions from its Uranium, Thorium, and Potassium content, disregarding daughter-product which may have a significant effect in some cases (eg 'pitchblende'). This involves multiplying the activity (A, in Bq) of each element by its specific gamma ray constant (Γ), which accounts for its unique gamma emissions. The total unshielded dose at 1 cm is then scaled by the square of the distance (r, in cm) and multiplied by a shielding factor (μshield). This calculation provides a 'worst-case' or 'maximum risk' estimate because it assumes the sample is a point source and entirely neglects any self-shielding where radiation is absorbed within the mineral itself, meaning actual doses will typically be lower. The resulting dose rate (D) is expressed in microsieverts per hour (μSv/h).
D = ((AU × ΓU) + (ATh × ΓTh) + (AK × ΓK)) / r2 × μshield
Fluorescence of Haiweeite
Weak dull-green
Other Information
Health Risks:
Contains uranium. Wash hands after handling. Do not lick or ingest. Store in uninhabited areas.
Internet Links for Haiweeite
mindat.org URL:
https://www.mindat.org/min-1802.html
Please feel free to link to this page.
Please feel free to link to this page.
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External Links:
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References for Haiweeite
Reference List:
McBurney, T. C., Murdoch, J. (1959) Haiweeite, a new uranium mineral from California. American Mineralogist, 44 (7-8) 839-843
(1962) International Mineralogical Association: Commission on New Minerals and Mineral Names. Mineralogical Magazine and Journal of the Mineralogical Society, 33 (258) 260-263 doi:10.1180/minmag.1962.033.258.09
de Carmargo, William G. R., Svisero, Darcy P. (1969) Haiweeite, a new occurrence in Brazil. American Mineralogist, 54 (5-6). 966-969
Burns, P. C. (2001) A new uranyl silicate sheet in the structure of haiweeite and comparison to other uranyl silicates. The Canadian Mineralogist, 39 (4) 1153-1160 doi:10.2113/gscanmin.39.4.1153
Burns, Peter C. (2005) U6+ minerals and inorganic compounds: insights into an expanded structural hierarchy of crystal structures. The Canadian Mineralogist, 43 (6) 1839-1894 doi:10.2113/gscanmin.43.6.1839
Frost, Ray L., Čejka, Jiří, Weier, Matt L., Martens, Wayde (2006) A Raman and infrared spectroscopic study of the uranyl silicates—Weeksite, soddyite and haiweeite: Part 2. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 63 (2) 305-312 doi:10.1016/j.saa.2005.05.015
Frost, Ray L., Čejka, Jiří, Weier, Matt L., Martens, Wayde, Kloprogge, J. Theo (2006) A Raman and infrared spectroscopic study of the uranyl silicates—Weeksite, soddyite and haiweeite. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 64 (2) 308-315 doi:10.1016/j.saa.2005.07.028
Localities for Haiweeite
Showing 23 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.
Austria | |
| Strasser (1989) |
Brazil | |
| A.M.D.V. Chaves (2005) |
| Pires et al. (2014) | |
| American Mineralogist: 84: 197-198. +1 other reference |
| de Carmargo et al. (1969) |
| Fosfatos e Silicatos Secundários de ... | |
Canada | |
| Alexandre et al. (2012) |
Chile | |
| A. Molina & M. Dini collections (based on XRD analysis) |
Czech Republic | |
| Pauliš P. et al. (Kutna Hora, issue 1) |
Greece | |
| Rieck et al. (2022) |
Japan | |
| K. Watanabe (1976) |
Mexico | |
| EDS analysis |
| Tony Peterson |
Namibia | |
| Rio Tinto Group |
| Niedermayr (2010) | |
Slovakia | |
| Martin Števko-unpublished |
Spain | |
| Sainz de Baranda Graf et al. (2026) |
| Tánago et al. (2012) |
Tajikistan | |
| Chukanov (2014) |
USA (TL) | |
| McBurney et al. (1959) +3 other references |
| www.shannonsminerals.com |
| Smith (1991) |
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Teófilo Otoni, Minas Gerais, Brazil