Emmonsite
A valid IMA mineral species - grandfathered
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About Emmonsite
Samuel Franklin Emmons
Formula:
Fe3+2(TeO3)3 · 2H2O
Colour:
Yellowish-green; light yellow-green in transmitted light.
Lustre:
Vitreous
Hardness:
5
Specific Gravity:
4.52 - 4.55
Crystal System:
Triclinic
Name:
For American economic geologist, Samuel Franklin Emmons (1841-1911), U.S. Geological Survey.
This page provides mineralogical data about Emmonsite.
Unique Identifiers
Mindat ID:
1377
Long-form identifier:
mindat:1:1:1377:8
Similar Names
| Amansite | A synonym of 'Oligoclase' | |
| Amensite | A synonym of Amesite | |
| Emmonite | A variety of Strontianite | (Sr,Ca)CO3 |
| Emmonsite (of Thomson) | A synonym of Strontianite |
IMA Classification of Emmonsite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
Fe3+2(Te4+O3)3·2H2O
First published:
1885
Classification of Emmonsite
4.JM.10
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
J : Arsenites, antimonites, bismuthites, sulfites, selenites, tellurites; iodates
M : Tellurites without additional anions, with H2O
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
J : Arsenites, antimonites, bismuthites, sulfites, selenites, tellurites; iodates
M : Tellurites without additional anions, with H2O
34.3.3.1
34 : SELENITES, TELLURITES AND SULFITES
3 : A2(XO3)3·xH2O
34 : SELENITES, TELLURITES AND SULFITES
3 : A2(XO3)3·xH2O
28.3.21
28 : Selenites, Selenates, Tellurites, and Tellurates
3 : Tellurites
28 : Selenites, Selenates, Tellurites, and Tellurates
3 : Tellurites
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 |
|---|---|---|
| Ems | 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 Emmonsite
Pronunciation:
| Play | Recorded by | Country |
|---|---|---|
| Jolyon Ralph | United Kingdom |
Physical Properties of Emmonsite
Vitreous
Transparency:
Translucent
Colour:
Yellowish-green; light yellow-green in transmitted light.
Hardness:
5 on Mohs scale
Cleavage:
Perfect
On {010}, perfect plus 2 unequal cleavages inclined relative to it, making plane angles of 85° and 95° in {010}.
On {010}, perfect plus 2 unequal cleavages inclined relative to it, making plane angles of 85° and 95° in {010}.
Density:
4.52 - 4.55 g/cm3 (Measured) 4.719 g/cm3 (Calculated)
Optical Data of Emmonsite
Type:
Biaxial (-)
RI values:
nα = 1.962 nβ = 2.09 nγ = 2.1 - 2.12
2V:
Measured: 23° , Calculated: 28° to 48°
Max. Birefringence:
δ = 0.138 - 0.158
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:
relatively strong r > v
Pleochroism:
Weak
Chemistry of Emmonsite
Mindat Formula:
Fe3+2(TeO3)3 · 2H2O
Element Weights:
Elements listed:
Crystallography of Emmonsite
Crystal System:
Triclinic
Class (H-M):
1 - Pinacoidal
Space Group:
P1
Cell Parameters:
a = 7.90(1) Å, b = 8.00(1) Å, c = 7.62(1) Å
α = 96.73°, β = 95°, γ = 84.47°
α = 96.73°, β = 95°, γ = 84.47°
Ratio:
a:b:c = 0.988 : 1 : 0.953
Unit Cell V:
474.64 ų (Calculated from Unit Cell)
Z:
2
Morphology:
Radially-configured or lichen-like groups of rough, acicular crystals; druses of thin scales; compact microcrystalline masses. Fibrous crusts with a small botryoidal surface to isolated globular aggregates.
Twinning:
Observed in microscopic crystals (Goldfield, Nevada).
Crystal Structure
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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) |
|---|---|---|---|---|---|---|---|
| 0015641 | Emmonsite | Pertlik F (1972) Der strukturtyp von emmonsit, {Fe2[TeO3]3*H2O}*xH2O (x=0-1) Tschermaks Mineralogische und Petrographische Mitteilungen 18 157-168 | 1972 | Tombstone, Arizona, USA | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 3.14 Å | (100) |
| 2.87 Å | (90) |
| 2.52 Å | (90) |
| 3.69 Å | (80) |
| 2.67 Å | (80) |
| 1.80 Å | (80) |
| 5.81 Å | (70) |
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] |
Geological Setting:
Oxidized zones of tellurium-bearing ore bodies.
Type Occurrence of Emmonsite
Place of Conservation of Type Material:
Yale University, New Haven, Connecticut, USA, 5.6300.
Harvard University, Cambridge, Massachusetts, USA, 97503.
Harvard University, Cambridge, Massachusetts, USA, 97503.
Associated Minerals at Type Locality:
Synonyms of Emmonsite
Other Language Names for Emmonsite
Common Associates
Associations Based on Photo Data:
| 24 photos of Emmonsite associated with Schmitterite | (UO2)(TeO3) |
| 15 photos of Emmonsite associated with Quartz | SiO2 |
| 11 photos of Emmonsite associated with Sonoraite | Fe3+(TeO3)(OH) · H2O |
| 9 photos of Emmonsite associated with Mackayite | Fe3+(Te4+2O5)(OH) |
| 8 photos of Emmonsite associated with Native Tellurium | Te |
| 8 photos of Emmonsite associated with Moctezumite | Pb(UO2)(TeO3)2 |
| 5 photos of Emmonsite associated with Native Gold | Au |
| 5 photos of Emmonsite associated with Goethite | Fe3+O(OH) |
| 4 photos of Emmonsite associated with Cuzticite | Fe3+2(TeO6) · 3H2O |
| 4 photos of Emmonsite associated with Bromargyrite | AgBr |
Related Minerals - Strunz-mindat Grouping
| 4.JM. | Wortupaite | MgNi2+2(Te4+O3)3 · 3H2O |
| 4.JM. | Rudolfhermannite | Fe3+2(Te4+O3)3(H2O) |
| 4.JM.05 | Zemannite | Mg0.5ZnFe3+(Te4+O3)3 · 4.5H2O |
| 4.JM.05 | Keystoneite | Mg0.5Ni2+Fe3+(Te4+O3)3 · 4.5H2O |
| 4.JM.05 | Kinichilite | Mg0.5Mn2+Fe3+(Te4+O3)3 · 4.5H2O |
| 4.JM.05 | Ilirneyite | Mg0.5ZnMn3+(Te4+O3)3 · 4.5H2O |
| 4.JM.10 | Blakeite | Fe3+2[TeO3]3 (?) |
| 4.JM.15 | Graemite | Cu[TeO3] · H2O |
| 4.JM.20 | Telluromandarinoite | Fe3+2Te3O9 · 6H2O |
| 4.JM.20 | Teineite | Cu2+(Te4+O3) · 2H2O |
| 4.JM.25 | Millsite | Cu2+(Te4+O3) · 2H2O |
Other Information
Notes:
Readily soluble in strong acids.
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 Emmonsite
mindat.org URL:
https://www.mindat.org/min-1377.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Emmonsite
Reference List:
Larsen, Esper S. (1921) The microscopic determination of the nonopaque minerals. Bulletin 679. US Geological Survey doi:10.3133/b679 p.71
Larsen, E.S.; Berman, H. (1934) The microscopic determination of the nonopaque minerals. Bulletin of the US Geological Survey Vol. 848. US Geological Survey p.1-266. doi:10.3133/b848 p.208
Frondel, Clifford, Pough, Fred H. (1944) Two new tellurites of iron: mackayite and blakeite. With new data on emmonsite and "durdenite.". American Mineralogist, 29 (5-6) 211-225
Localities for Emmonsite
Showing 48 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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Moctezuma Mine, Moctezuma, Moctezuma Municipality, Sonora, Mexico