Stewartite
A valid IMA mineral species - grandfathered
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About Stewartite
Stewart Mine on Pala Mountain
Stewart Mine, Tourmaline Queen Mountain, Pala, Pala Mining District, San Diego County, California, USA
Stewart Mine, Tourmaline Queen Mountain, Pala, Pala Mining District, San Diego County, California, USA
Formula:
Mn2+Fe3+2(PO4)2(OH)2 · 8H2O
Colour:
Yellow to brownish yellow
Lustre:
Sub-Vitreous, Resinous, Silky
Specific Gravity:
2.94
Crystal System:
Triclinic
Member of:
Name:
Named in 1912 by Waldemar T. Schaller for its discovery locality, the Stewart Lithia pegmatite, Pala, California, USA, that was owned by John Stewart of Los Angeles, Caliornia, USA.
Type Locality:
Polymorph of:
Isostructural with:
Golden yellow bladed crystals, usually with an acute termination. May occasionally show a similar less acute termination similar to laueite. Note: stewartite may have very similar appearance to laueite, but laueite is usually conspicuously striated, while stewartite usually isn't.
Unique Identifiers
Mindat ID:
3772
Long-form identifier:
mindat:1:1:3772:9
Similar Names
| Stewartite (of Sutton) | A variety of Diamond | C |
Classification of Stewartite
Laueite structure archetype
In stewartite, the M1 site is occupied by Mn2+ and the M2 and M3 sites are occupied by Fe3+. The X site is a phosphate group.
IMA Classification of Stewartite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
Mn2+Fe3+2(PO4)2(OH)2·8H2O
First published:
1912
Type description reference:
8.DC.30
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
C : With only medium-sized cations, (OH, etc.):RO4 = 1:1 and < 2:1
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
C : With only medium-sized cations, (OH, etc.):RO4 = 1:1 and < 2:1
42.11.10.2
42 : HYDRATED PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
11 : (AB)3(XO4)2Zq·xH2O
42 : HYDRATED PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
11 : (AB)3(XO4)2Zq·xH2O
19.12.27
19 : Phosphates
12 : Phosphates of Mn
19 : Phosphates
12 : Phosphates of Mn
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 |
|---|---|---|
| Stw | 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 Stewartite
Sub-Vitreous, Resinous, Silky
Transparency:
Transparent, Translucent
Colour:
Yellow to brownish yellow
Streak:
White
Tenacity:
Very brittle
Cleavage:
None Observed
Density:
2.94 g/cm3 (Measured) 2.48 g/cm3 (Calculated)
Optical Data of Stewartite
Type:
Biaxial (-)
RI values:
nα = 1.612 - 1.630 nβ = 1.653 - 1.658 nγ = 1.660 - 1.681
Birefringence:
0.050
Max. Birefringence:
δ = 0.048 - 0.051
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.
No measured or calculated 2V is on file for this mineral, so the value used here (66°) is estimated from its recorded refractive indices and optic sign, not from a direct 2V measurement.
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.
No measured or calculated 2V is on file for this mineral, so the value used here (66°) is estimated from its recorded refractive indices and optic sign, not from a direct 2V measurement.
Dispersion:
r < v strong
Pleochroism:
Visible
Comments:
X = Colourless
Y = Light yellow
Z = Yellow
Y = Light yellow
Z = Yellow
Chemistry of Stewartite
Mindat Formula:
Mn2+Fe3+2(PO4)2(OH)2 · 8H2O
Element Weights:
Crystallography of Stewartite
Crystal System:
Triclinic
Class (H-M):
1 - Pinacoidal
Space Group:
P1
Setting:
P1
Cell Parameters:
a = 10.398 Å, b = 10.672 Å, c = 7.223 Å
α = 90.10°, β = 109.10°, γ = 71.83°
α = 90.10°, β = 109.10°, γ = 71.83°
Ratio:
a:b:c = 0.974 : 1 : 0.677
Unit Cell V:
715.12 ų (Calculated from Unit Cell)
Z:
2
Morphology:
Crystals minute; tufts of fibers.
Twinning:
Twins showing small "fish-tail" re-entry angles {010}
Crystal Structure
Load
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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Labels
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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) |
|---|---|---|---|---|---|---|---|
| 0000432 | Stewartite | Moore P B, Araki T (1974) Stewartite, MnFe2(OH)2(H2O)6[PO4]2.2H2O: Its atomic arrangement American Mineralogist 59 1272-1276 |  | 1974 | 0 | 293 |
CIF Raw Data - click here to close
Epitaxial Relationships of Stewartite
Epitaxial Minerals:
| 'Laueite' | Mn2+Fe3+2(PO4)2(OH)2 · 8H2O |
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 10.04 Å | (100) |
| 6.73 Å | (70) |
| 5.035 Å | (50) |
| 3.925 Å | (50) |
| 3.925 Å | (50) |
| 3.03 Å | (40) |
| 2.60 Å | (40) |
| 2.489 Å | (40) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 4b: Highly evolved igneous rocks | >3.0 |
| 34 : Complex granite pegmatites | |
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| 47c : [Carbonates, phosphates, borates, nitrates] | |
| 47e : [Vanadates, chromates, manganates] |
Type Occurrence of Stewartite
General Appearance of Type Material:
Fine fibers arranged normal to the cleavage cracks of the lithiophilite.
Place of Conservation of Type Material:
National Museum of Natural History, Washington, D.C., USA, number 93656.
Geological Setting of Type Material:
In pegmatite, as an alteration product of lithiophilite which it replaces along cleavage cracks.
Associated Minerals at Type Locality:
Synonyms of Stewartite
Other Language Names for Stewartite
Relationship of Stewartite to other Species
Member of:
Other Members of Laueite Group:
| Curetonite | Ba(Al,Ti)(PO4)(OH,O)F | Mon. 2/m |
| Ferrolaueite | Fe2+Fe3+2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
| Gordonite | MgAl2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
| Kastningite | (Mn2+,Fe2+,Mg)Al2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
| Kummerite | Mn2+Fe3+Al(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
| Laueite | Mn2+Fe3+2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
| Mangangordonite | Mn2+Al2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
| Paravauxite | Fe2+Al2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
| Sigloite | Fe3+Al2(PO4)2(OH)3 · 7H2O | Tric. 1 : P1 |
| Ushkovite | MgFe3+2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
Common Associates
Associations Based on Photo Data:
| 72 photos of Stewartite associated with Laueite | Mn2+Fe3+2(PO4)2(OH)2 · 8H2O |
| 67 photos of Stewartite associated with Strunzite | Mn2+Fe3+2(PO4)2(OH)2 · 6H2O |
| 56 photos of Stewartite associated with Strengite | FePO4 · 2H2O |
| 41 photos of Stewartite associated with Rockbridgeite | (Fe2+0.5Fe3+0.5)2Fe3+3(PO4)3(OH)5 |
| 40 photos of Stewartite associated with Phosphosiderite | FePO4 · 2H2O |
| 23 photos of Stewartite associated with Pseudolaueite | Mn2+Fe3+2(PO4)2(OH)2 · 8H2O |
| 17 photos of Stewartite associated with Mitridatite | Ca2Fe3+3(PO4)3O2 · 3H2O |
| 17 photos of Stewartite associated with Beraunite | Fe3+6(PO4)4O(OH)4 · 6H2O |
| 15 photos of Stewartite associated with Hureaulite | Mn2+5(PO3OH)2(PO4)2 · 4H2O |
| 13 photos of Stewartite associated with Bermanite | Mn2+Mn3+2(PO4)2(OH)2 · 4H2O |
Related Minerals - Strunz-mindat Grouping
| 8.DC. | Ferroberaunite | Fe2+Fe3+5(PO4)4(OH)5 · 6H2O |
| 8.DC. | Césarferreiraite | Fe2+ Fe3+2(AsO4)2(OH)2 · 8H2O |
| 8.DC. | Ferrivauxite | Fe3+Al2(PO4)2(OH)3 · 5H2O |
| 8.DC. | Ianbruceite | Zn2(AsO4)(OH) · 3H2O |
| 8.DC.05 | Nissonite | Cu2Mg2(PO4)2(OH)2 · 5H2O |
| 8.DC.07 | Euchroite | Cu2(AsO4)(OH) · 3H2O |
| 8.DC.10 | Legrandite | Zn2(AsO4)(OH) · H2O |
| 8.DC.12 | Strashimirite | Cu8(AsO4)4(OH)4 · 5H2O |
| 8.DC.15 | Earlshannonite | Mn2+Fe3+2(PO4)2(OH)2 · 4H2O |
| 8.DC.15 | Kunatite | CuFe3+2(PO4)2(OH)2 · 4H2O |
| 8.DC.15 | 'UM2006-27-PO:FeHZn' | ZnFe3+2(PO4)2(OH)2 · 4H2O |
| 8.DC.15 | 'UKI-2006-(PO:AlCuFeH)' | Fe2+Al3+2(PO4)2(OH)2 · 4H2O |
| 8.DC.15 | Cobaltarthurite | CoFe3+2(AsO4)2(OH)2 · 4H2O |
| 8.DC.15 | Arthurite | CuFe3+2(AsO4)2(OH)2 · 4H2O |
| 8.DC.15 | Ojuelaite | ZnFe3+2(AsO4)2(OH)2 · 4H2O |
| 8.DC.15 | Whitmoreite | Fe2+Fe3+2(PO4)2(OH)2 · 4H2O |
| 8.DC.15 | Bendadaite | Fe2+Fe3+2(AsO4)2(OH)2 · 4H2O |
| 8.DC.17 | Kleemanite | ZnAl2(PO4)2(OH)2 · 3H2O |
| 8.DC.20 | Magnesiobermanite | MgMn3+2(PO4)2(OH)2 · 4H2O |
| 8.DC.20 | Bermanite | Mn2+Mn3+2(PO4)2(OH)2 · 4H2O |
| 8.DC.20 | Coralloite | Mn2+Mn3+2(AsO4)2(OH)2 · 4H2O |
| 8.DC.22 | Kovdorskite | Mg2(PO4)(OH) · 3H2O |
| 8.DC.25 | Zincostrunzite | ZnFe3+2(PO4)2(OH)2 · 6.5H2O |
| 8.DC.25 | Metavauxite | Fe2+Al2(PO4)2(OH)2 · 8H2O |
| 8.DC.25 | Metavivianite | Fe2+Fe3+2(PO4)2(OH)2 · 6H2O |
| 8.DC.25 | Ferristrunzite | Fe3+Fe3+2(PO4)2(OH)3 · 5H2O |
| 8.DC.25 | Strunzite | Mn2+Fe3+2(PO4)2(OH)2 · 6H2O |
| 8.DC.25 | Ferrostrunzite | Fe2+Fe3+2(PO4)2(OH)2 · 6H2O |
| 8.DC.27 | Beraunite | Fe3+6(PO4)4O(OH)4 · 6H2O |
| 8.DC.27 | Tvrdýite | Fe2+Fe3+2Al3(PO4)4(OH)5(H2O)4 · 2H2O |
| 8.DC.27 | Zincoberaunite | ZnFe3+5(PO4)4(OH)5 · 6H2O |
| 8.DC.30 | Maghrebite | MgAl2(AsO4)2(OH)2 · 8H2O |
| 8.DC.30 | Ferrolaueite | Fe2+Fe3+2(PO4)2(OH)2 · 8H2O |
| 8.DC.30 | Ushkovite | MgFe3+2(PO4)2(OH)2 · 8H2O |
| 8.DC.30 | Laueite | Mn2+Fe3+2(PO4)2(OH)2 · 8H2O |
| 8.DC.30 | Paravauxite | Fe2+Al2(PO4)2(OH)2 · 8H2O |
| 8.DC.30 | Sigloite | Fe3+Al2(PO4)2(OH)3 · 7H2O |
| 8.DC.30 | Nordgauite | MnAl2(PO4)2(F,OH)2 · 5H2O |
| 8.DC.30 | Kayrobertsonite | [MnAl2(PO4)2(OH)2(H2O)4] · 2H2O |
| 8.DC.30 | Kummerite | Mn2+Fe3+Al(PO4)2(OH)2 · 8H2O |
| 8.DC.30 | Mangangordonite | Mn2+Al2(PO4)2(OH)2 · 8H2O |
| 8.DC.30 | Gordonite | MgAl2(PO4)2(OH)2 · 8H2O |
| 8.DC.30 | Kastningite | (Mn2+,Fe2+,Mg)Al2(PO4)2(OH)2 · 8H2O |
| 8.DC.30 | Pseudolaueite | Mn2+Fe3+2(PO4)2(OH)2 · 8H2O |
| 8.DC.32 | Kamarizaite | Fe3+3(AsO4)2(OH)3 · 3H2O |
| 8.DC.32 | Tinticite | Fe3+3(PO4)2(OH)3 · 3H2O |
| 8.DC.35 | Vauxite | Fe2+Al2(PO4)2(OH)2 · 6H2O |
| 8.DC.37 | Vantasselite | Al4(PO4)3(OH)3 · 9H2O |
| 8.DC.40 | Cacoxenite | Fe3+24AlO6(PO4)17(OH)12 · 75H2O |
| 8.DC.45 | Souzalite | Mg3Al4(PO4)4(OH)6 · 2H2O |
| 8.DC.45 | Gormanite | (Fe2+,Mg)3(Al,Fe3+)4(PO4)4(OH)6 · 2H2O |
| 8.DC.47 | Kingite | Al3(PO4)2F2(OH) · 7H2O |
| 8.DC.50 | Allanpringite | Fe3+3(PO4)2(OH)3 · 5H2O |
| 8.DC.50 | Fluorwavellite | Al3(PO4)2(OH)2F · 5H2O |
| 8.DC.50 | Wavellite | Al3(PO4)2(OH)3 · 5H2O |
| 8.DC.52 | Kribergite | Al5(PO4)3(SO4)(OH)4 · 4H2O |
| 8.DC.55 | Mapimite | Zn2Fe3+3(AsO4)3(OH)4 · 10H2O |
| 8.DC.57 | Ogdensburgite | Ca2Fe3+4(Zn,Mn2+)(AsO4)4(OH)6 · 6H2O |
| 8.DC.60 | Cloncurryite | Cu0.5(VO)0.5Al2(PO4)2F2 · 5H2O |
| 8.DC.60 | Nevadaite | (Cu2+,Al,V3+)6Al8(PO4)8F8(OH)2 · 22H2O |
| 8.DC.62 | Kenngottite | Mn2+3Fe3+4(PO4)4(OH)6(H2O)2 |
| 8.DC.67 | Molinelloite | Cu(H2O)(OH)V4+O(V5+O4) |
| 8.DC.70 | Whitecapsite | H16Fe2+5Fe3+14Sb3+6(AsO4)18O16 · 120H2O |
| 8.DC.75 | Heimite | PbCu2(AsO4)(OH)3 · 2H2O |
| 8.DC.80 | Lednevite | Cu[PO3(OH)] · H2O |
Fluorescence of Stewartite
Not fluorescent in UV
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 Stewartite
mindat.org URL:
https://www.mindat.org/min-3772.html
Please feel free to link to this page.
Please feel free to link to this page.
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Mineral Dealers:
References for Stewartite
Reference List:
Lacroix, A. (1910) Minéralogie de la France et de ses colonies Vol. 4. Library Polytechnique, Paris. p.506 - as "Mineral A"
Moore, Paul Brian, Araki, Takaharu (1974) Stewartite, Mn2+Fe3+2(OH)2(H2O)6[PO4]2·2H2O: Its atomic arrangement. American Mineralogist, 59 (11-12) 1272-1276
Rossman, George R. (1976) Spectroscopic and magnetic studies of ferric iron hydroxy sulfates: the series Fe(OH)SO4·nH2O and the jarosites. American Mineralogist, 61 (5-6) 398-404
Localities for Stewartite
Showing 60 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.
Argentina | |
| Gay et al. (1991) +1 other reference |
Brazil | |
| e-rocks.com (n.d.) |
| King et al. (1993) | |
| King (n.d.) |
| Sergio Varvello collection |
| Murdoch (1955) |
Europe | |
| Berbain et al. (2012) | |
France | |
| Boisson (1988) |
| Chatenet et al. (2008) |
| Berbain et al. (2012) |
Germany | |
| Walenta (1992) +1 other reference |
| Weiß (1990) +1 other reference |
| Christof Schäfer Collection |
| web.archive.org (2001) +1 other reference | |
| Wittern (2001) +1 other reference | |
| Pöllmann et al. (2005) |
Japan | |
| Matsubara and Kato (1996) |
Madagascar | |
| Behier (1960) |
Morocco | |
| Favreau (2012) |
Namibia | |
| Keller et al. (1989) |
New Zealand | |
| Stott (pers. notes) |
Portugal | |
| Alves (n.d.) |
| Pedro Alves collection. Characterized ... |
| Schnorrer-Köhler et al. (1991) |
| Alves (n.d.) | |
| Sergio Varvello collection |
| Self-collected by Pedro Alves. |
| Neves (1960) |
| Gramaccioli (1981) +1 other reference |
| Mineralien Atlas | |
| Nunes (n.d.) |
Rwanda | |
| Bertossa (1968) +1 other reference |
USA | |
| Dean (1995) |
| Rocks & Minerals: 70 (5) | |
| AmMin 67: 97-113 (1982) |
| Jahns (1952) |
| Schaller (1912) +1 other reference |
| San Diego Mining Company (2023) | |
| Schooner (circa 1985) |
| King et al. (1994) +1 other reference |
| Mineral News (1995) +2 other references |
| King et al. (1994) |
| Palache et al. (1951) | |
| King et al. (1994) +1 other reference |
| Thompson et al. (1998) |
| Rocks & Min. 80:251 |
| Palache et al. (1951) +2 other references | |
| Palache et al. (1951) +2 other references | |
| Rocks & Min. +2 other references | |
| Smith (2005) | |
| Rocks & Minerals 80:4 pp234-241 +1 other reference |
| |
| Christophe Boutry collection |
| Smith et al. (2000) |
| Rocks & Minerals: 60: 117. +1 other reference |
| Smith et al. (2000) |
| Campbell et al. (1985) |
| Smith et al. (2000) | |
| Rocks & Minerals: 67 (6) |
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Bull Moose Mine, Custer, Custer Mining District, Custer County, South Dakota, USA