Raygrantite
A valid IMA mineral species
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About Raygrantite
Ray Grant
Formula:
Pb10Zn(SO4)6(SiO4)2(OH)2
Colour:
Colourless
Lustre:
Vitreous
Hardness:
3
Specific Gravity:
6.374 (Calculated)
Crystal System:
Triclinic
Member of:
Name:
Named after Dr. Raymond W. Grant (b. October 25, 1939) retired professor of geology (Lafayette College, University of Vermont, Mesa Community College). Founder and former curator of the Pinal Geology and Mineral Museum in Coolidge, Arizona. Past President of the Pinal Geology and Mineral Society; Life Member and Past President of the Mineralogical Society of Arizona; and Past Chairman of the Flagg Mineral Foundation. Lead author of the Mineralogy of Arizona (4th edition), mineralogist, and Arizona thumbnail collector currently (as of 2026) residing in Mesa, Arizona.
Type Locality:
Isostructural with:
The S (or sulfate) analogue of hemihedrite, and S-Zn analogue of iranite.
The crystal structure consists of slabs || (120), which contain sulfate and silicate tetrahedra and ZnO4(OH)2 octahedra. Pb cations held those polyhedra together. There is a wide range of Pb–O bond distances.
The crystal structure consists of slabs || (120), which contain sulfate and silicate tetrahedra and ZnO4(OH)2 octahedra. Pb cations held those polyhedra together. There is a wide range of Pb–O bond distances.
Unique Identifiers
Mindat ID:
43868
Long-form identifier:
mindat:1:1:43868:9
IMA Classification of Raygrantite
Approved
IMA Formula:
Pb2+10Zn2+(S6+O4)6(SiO4)2(OH)2
Approval year:
2013
First published:
2017
Type description reference:
Yang, Hexiong, Andrade, Marcelo B., Downs, Robert T., Gibbs, Ronald B., Jenkins, Robert A. (2016) Raygrantite, Pb10Zn(SO4)6(SiO4)2(OH)2,a new mineral isostructural with iranite, from the Big Horn Mountains, Maricopa County, Arizona, USA. The Canadian Mineralogist, 54 (3) 625-634 doi:10.3749/canmin.1500058
Classification of Raygrantite
7.FC.15
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
F : Chromates
C : With PO4, AsO4, SiO4
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
F : Chromates
C : With PO4, AsO4, SiO4
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 |
|---|---|---|
| Rgr | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Pronunciation of Raygrantite
Pronunciation:
| Play | Recorded by | Country |
|---|---|---|
| Jolyon Ralph | United Kingdom |
Physical Properties of Raygrantite
Vitreous
Transparency:
Transparent
Colour:
Colourless
Streak:
White
Hardness:
3 on Mohs scale
Comment:
Ca. 3
Tenacity:
Brittle
Cleavage:
Distinct/Good
on {120}
on {120}
Parting:
Not observed
Density:
6.374 g/cm3 (Calculated)
Optical Data of Raygrantite
Type:
Biaxial (+)
RI values:
nα = 1.915(7) nβ = 1.981(7) nγ = 2.068(9)
2V:
Measured: 76° (2), Calculated: 85°
Max. Birefringence:
δ = 0.153
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.
Chemistry of Raygrantite
Mindat Formula:
Pb10Zn(SO4)6(SiO4)2(OH)2
Element Weights:
Crystallography of Raygrantite
Crystal System:
Triclinic
Class (H-M):
1 - Pinacoidal
Space Group:
P1
Cell Parameters:
a = 9.3175(4) Å, b = 11.1973(5) Å, c = 10.8318(5) Å
α = 120.374(2)°, β = 90.511(2)°, γ = 56.471(2)°
α = 120.374(2)°, β = 90.511(2)°, γ = 56.471(2)°
Ratio:
a:b:c = 0.832 : 1 : 0.967
Unit Cell V:
753.13 ų
Twinning:
Fish-tail type, pervasive on (1 2 -1)
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 4.753 Å | (56) |
| 4.288 Å | (32) |
| 3.267 Å | (63) |
| 3.102 Å | (100) |
| 2.996 Å | (29) |
| 2.851 Å | (35) |
| 2.783 Å | (31) |
| 2.707 Å | (31) |
Locality:
Reference:
Yang, Hexiong, Andrade, Marcelo B., Downs, Robert T., Gibbs, Ronald B., Jenkins, Robert A. (2016) Raygrantite, Pb10Zn(SO4)6(SiO4)2(OH)2,a new mineral isostructural with iranite, from the Big Horn Mountains, Maricopa County, Arizona, USA. The Canadian Mineralogist, 54 (3) 625-634 doi:10.3749/canmin.1500058
Comments:
From Type Description.
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| 47b : [Sulfates and sulfites] |
Type Occurrence of Raygrantite
General Appearance of Type Material:
Bladed crystals with striations || c.
Place of Conservation of Type Material:
Type material is deposited in the collections of the University of Arizona Mineral Museum, Tucson, Arizona, USA, catalogue number 19345, and the RRUFF Project, deposition number R120151 .
Geological Setting of Type Material:
Believed to be secondary in origin as a remnant of a galena-pyrite-chalcopyrite vein. The locality is basement-hosted narrow quartz pods and veins associated with late Cretaceous intrusives.
Associated Minerals at Type Locality:
Reference:
Yang, Hexiong, Andrade, Marcelo B., Downs, Robert T., Gibbs, Ronald B., Jenkins, Robert A. (2016) Raygrantite, Pb10Zn(SO4)6(SiO4)2(OH)2,a new mineral isostructural with iranite, from the Big Horn Mountains, Maricopa County, Arizona, USA. The Canadian Mineralogist, 54 (3) 625-634 doi:10.3749/canmin.1500058
Synonyms of Raygrantite
Other Language Names for Raygrantite
Dutch:Raygrantiet
German:Raygrantit
Relationship of Raygrantite to other Species
Member of:
Other Members of Iranite Group:
| Hemihedrite | Pb10Zn(CrO4)6(SiO4)2(OH)2 | Tric. 1 : P1 |
| Iranite | Pb10Cu(CrO4)6(SiO4)2(OH)2 | Tric. 1 : P1 |
Common Associates
Related Minerals - Strunz-mindat Grouping
| 7.FC.05 | Vauquelinite | Pb2Cu(CrO4)(PO4)(OH) |
| 7.FC.10 | Fornacite | Pb2Cu(CrO4)(AsO4)(OH) |
| 7.FC.10 | Molybdofornacite | Pb2Cu(MoO4,CrO4)(AsO4,PO4)(OH) |
| 7.FC.15 | Hemihedrite | Pb10Zn(CrO4)6(SiO4)2(OH)2 |
| 7.FC.15 | Iranite | Pb10Cu(CrO4)6(SiO4)2(OH)2 |
| 7.FC.20 | Embreyite | Pb5(CrO4)2(PO4)2 · H2O |
| 7.FC.20 | Cassedanneite | Pb5(CrO4)2(VO4)2 · H2O |
Other Information
Notes:
Insoluble in water, acetone or HCl acid.
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 Raygrantite
mindat.org URL:
https://www.mindat.org/min-43868.html
Please feel free to link to this page.
Please feel free to link to this page.
Search Engines:
External Links:
Mineral Dealers:
References for Raygrantite
Reference List:
Williams, P. A., Hatert, F., Pasero, M., Mills, S. J. (2013) New minerals and nomenclature modifications approved in 2013. CNMNC Newsletter No 16. Mineralogical Magazine, 77 (6) 2695-2709 doi:10.1180/minmag.2013.077.6.01
Yang, Hexiong, Andrade, Marcelo B., Downs, Robert T., Gibbs, Ronald B., Jenkins, Robert A. (2016) Raygrantite, Pb10Zn(SO4)6(SiO4)2(OH)2,a new mineral isostructural with iranite, from the Big Horn Mountains, Maricopa County, Arizona, USA. The Canadian Mineralogist, 54 (3) 625-634 doi:10.3749/canmin.1500058
Localities for Raygrantite
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) | |
| Williams et al. (2013) +2 other references |
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Evening Star Mine, Tiger Wash, Tonopah, Osborn Mining District, Maricopa County, Arizona, USA