Changoite
A valid IMA mineral species
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About Changoite
Formula:
Na2Zn(SO4)2 · 4H2O
Colour:
Colorless
Lustre:
Vitreous
Hardness:
2 - 3
Specific Gravity:
2.50
Crystal System:
Monoclinic
Member of:
Name:
Named after the Changos people, the early former inhabitants of northern Chile.
Type Locality:
Unique Identifiers
Mindat ID:
6861
Long-form identifier:
mindat:1:1:6861:7
IMA Classification of Changoite
Approved
IMA Formula:
Na2Zn2+(S6+O4)2·4H2O
Approval year:
1997
First published:
1999
Classification of Changoite
7.CC.50
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
C : Sulfates (selenates, etc.) without additional anions, with H2O
C : With medium-sized and large cations
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
C : Sulfates (selenates, etc.) without additional anions, with H2O
C : With medium-sized and large cations
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 |
|---|---|---|
| Cgo | 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 Changoite
Pronunciation:
| Play | Recorded by | Country |
|---|---|---|
| Jolyon Ralph | United Kingdom |
Physical Properties of Changoite
Vitreous
Transparency:
Transparent
Colour:
Colorless
Streak:
White
Hardness:
2 - 3 on Mohs scale
Density:
2.50 g/cm3 (Measured) 2.507 g/cm3 (Calculated)
Optical Data of Changoite
Type:
Biaxial (-)
RI values:
nα = 1.507 nβ = 1.512 nγ = 1.517
Max. Birefringence:
δ = 0.010
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:
Low (negative)
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 (90°) 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 (90°) is estimated from its recorded refractive indices and optic sign, not from a direct 2V measurement.
Dispersion:
none
Comments:
Synthetic
Chemistry of Changoite
Mindat Formula:
Na2Zn(SO4)2 · 4H2O
Element Weights:
Crystallography of Changoite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P21/b
Cell Parameters:
a = 5.5075 Å, b = 8.2127 Å, c = 11.0559 Å
β = 99.958(10)°
β = 99.958(10)°
Ratio:
a:b:c = 0.671 : 1 : 1.346
Unit Cell V:
492.54 ų
Z:
2
Comment:
synthetic
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
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
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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
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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) |
|---|---|---|---|---|---|---|---|
| 0009212 | Changoite | Giglio M (1958) Die kristallstruktur von Na2Zn(SO4)2*4H2O (Zn-blodit) Acta Crystallographica 11 789-794 |  | 1958 | synthetic | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 4.550 Å | (58) |
| 4.245 Å | (32) |
| 3.325 Å | (25) |
| 3.289 Å | (100) |
| 3.245 Å | (25) |
| 3.262 Å | (35) |
| 2.631 Å | (27) |
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 Changoite
General Appearance of Type Material:
Seams, up to 10 mm wide, of anhedral,
colorless crystals coated with thenardite
colorless crystals coated with thenardite
Place of Conservation of Type Material:
Mineralogical Museum of the University of Hamburg, Germany
Geological Setting of Type Material:
Oxidation zone of Cu-Zn deposit
Associated Minerals at Type Locality:
Synonyms of Changoite
Other Language Names for Changoite
Relationship of Changoite to other Species
Member of:
Other Members of Blödite Group:
| Blödite | Na2Mg(SO4)2 · 4H2O | Mon. 2/m : P21/b |
| Cobaltoblödite | Na2Co(SO4)2 · 4H2O | Mon. 2/m : P21/b |
| Manganoblödite | Na2Mn(SO4)2 · 4H2O | Mon. 2/m : P21/b |
| Nickelblödite | Na2Ni(SO4)2 · 4H2O | Mon. 2/m : P21/b |
Common Associates
Associations Based on Photo Data:
| 9 photos of Changoite associated with Kröhnkite | Na2Cu(SO4)2 · 2H2O |
| 5 photos of Changoite associated with Caracolite | Na3Pb2(SO4)3Cl |
| 1 photo of Changoite associated with Sphalerite | ZnS |
| 1 photo of Changoite associated with Quartz | SiO2 |
| 1 photo of Changoite associated with 'Chalcedony' | SiO2 |
| 1 photo of Changoite associated with Pseudomeisserite-(NH4) | (NH4)2Na4[(UO2)2(SO4)5] · 4H2O |
| 1 photo of Changoite associated with Ferrinatrite | Na3Fe(SO4)3 · 3H2O |
Related Minerals - Strunz-mindat Grouping
| 7.CC. | Cobaltoblödite | Na2Co(SO4)2 · 4H2O |
| 7.CC. | Andychristyite | PbCu2+Te6+O5(H2O) |
| 7.CC. | Ammoniovoltaite | (NH4)2Fe2+5Fe3+3Al(SO4)12(H2O)18 |
| 7.CC.05 | Krausite | KFe(SO4)2 · H2O |
| 7.CC.10 | Tamarugite | NaAl(SO4)2 · 6H2O |
| 7.CC.15 | Mendozite | NaAl(SO4)2 · 11H2O |
| 7.CC.15 | Kalinite | KAl(SO4)2 · 11H2O |
| 7.CC.20 | Alum-(Na) | NaAl(SO4)2 · 12H2O |
| 7.CC.20 | Lonecreekite | (NH4)Fe3+(SO4)2 · 12H2O |
| 7.CC.20 | Alum-(K) | KAl(SO4)2 · 12H2O |
| 7.CC.20 | Tschermigite | (NH4)Al(SO4)2 · 12H2O |
| 7.CC.20 | Lanmuchangite | Tl+Al(SO4)2 · 12H2O |
| 7.CC.25 | Zincovoltaite | K2Zn5Fe3+3Al(SO4)12 · 18H2O |
| 7.CC.25 | Voltaite | K2Fe2+5Fe3+3Al(SO4)12 · 18H2O |
| 7.CC.25 | Magnesiovoltaite | K2Mg5Fe3+3Al(SO4)12 · 18H2O |
| 7.CC.25 | Pertlikite | K2(Fe2+,Mg)2(Mg,Fe3+)4Fe3+2Al(SO4)12 · 18H2O |
| 7.CC.25 | Ammoniomagnesiovoltaite | (NH4)2Mg2+5Fe3+3Al(SO4)12 · 18H2O |
| 7.CC.30 | Kröhnkite | Na2Cu(SO4)2 · 2H2O |
| 7.CC.35 | Ferrinatrite | Na3Fe(SO4)3 · 3H2O |
| 7.CC.40 | Goldichite | KFe(SO4)2 · 4H2O |
| 7.CC.45 | Löweite | Na12Mg7(SO4)13 · 15H2O |
| 7.CC.50 | Nickelblödite | Na2Ni(SO4)2 · 4H2O |
| 7.CC.50 | Blödite | Na2Mg(SO4)2 · 4H2O |
| 7.CC.55 | Leonite | K2Mg(SO4)2 · 4H2O |
| 7.CC.55 | Mereiterite | K2Fe(SO4)2 · 4H2O |
| 7.CC.60 | Nickelpicromerite | K2Ni(SO4)2 · 6H2O |
| 7.CC.60 | Nickelboussingaultite | (NH4)2Ni(SO4)2 · 6H2O |
| 7.CC.60 | Katerinopoulosite | (NH4)2Zn(SO4)2 · 6H2O |
| 7.CC.60 | Picromerite | K2Mg(SO4)2 · 6H2O |
| 7.CC.60 | Cyanochroite | K2Cu(SO4)2 · 6H2O |
| 7.CC.60 | Mohrite | (NH4)2Fe(SO4)2 · 6H2O |
| 7.CC.60 | Boussingaultite | (NH4)2Mg(SO4)2 · 6H2O |
| 7.CC.65 | Polyhalite | K2Ca2Mg(SO4)4 · 2H2O |
| 7.CC.70 | Leightonite | K2Ca2Cu(SO4)4 · 2H2O |
| 7.CC.75 | Amarillite | NaFe(SO4)2 · 6H2O |
| 7.CC.80 | Konyaite | Na2Mg(SO4)2 · 5H2O |
| 7.CC.85 | Wattevilleite | Na2Ca(SO4)2 · 4H2O (?) |
| 7.CC.85 | Xocolatlite | Ca2Mn4+2(Te6+O6)2 · H2O |
| 7.CC.90 | Eckhardite | (Ca,Pb)Cu2+Te6+O5(H2O) |
Fluorescence of Changoite
Not fluorescent
Other Information
Notes:
Water soluble
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 Changoite
mindat.org URL:
https://www.mindat.org/min-6861.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Changoite
Localities for Changoite
Showing 9 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.
Chile (TL) | |
| Schlüter et al. (1999) +2 other references |
| SEM-EDS by Joy DEsor |
| Samples analysed by Dr. Jochen Schluter | |
Greece | |
| Rieck et al. (2018) |
Namibia | |
| Dr. Ing. Thomas Krassmann specimen at Munich Show 2012 (Krassmann & Kolitsch, to be published) |
Peru | |
| Cosme R. Pérez-Puig (2008) +1 other reference |
Spain | |
| Calvo Rebollar et al. (2022) |
USA | |
| Olds et al. (2023) |
Vietnam | |
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La Compañia Mine, Sierra Gorda, Antofagasta Province, Antofagasta, Chile