Chessexite
A valid IMA mineral species
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About Chessexite
R. Chessex, professeur en sciences, vice-recteur de l'Université
Formula:
(Na,K)4Ca2(Mg,Zn)3Al8(SO4)10(SiO4)2 · 40H2O
Colour:
White
Lustre:
Silky
Specific Gravity:
2.21 (Calculated)
Crystal System:
Orthorhombic
Name:
Named in honor of Ronald Chessex (b. 1929 Lausanne, Switzerland), petrographer and professor, University of Geneva, Geneva, Switzerland.
This page provides mineralogical data about Chessexite.
Unique Identifiers
Mindat ID:
996
Long-form identifier:
mindat:1:1:996:4
IMA Classification of Chessexite
Approved
IMA Formula:
Na4Ca2Mg3Al8(SiO4)2(S6+O4)10(OH)10·40H2O
Approval year:
1981
Classification of Chessexite
7.DG.35
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
D : Sulfates (selenates, etc.) with additional anions, with H2O
G : With large and medium-sized cations; with NO3, CO3, B(OH)4, SiO4 or IO3
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
D : Sulfates (selenates, etc.) with additional anions, with H2O
G : With large and medium-sized cations; with NO3, CO3, B(OH)4, SiO4 or IO3
32.4.6.1
32 : COMPOUND SULFATES
4 : Hydrated Compound Sulfates containing Hydroxyl or Halogen
32 : COMPOUND SULFATES
4 : Hydrated Compound Sulfates containing Hydroxyl or Halogen
17.10.16
17 : Silicates Containing other Anions
10 : Silicates with sulphate, molybdate or tungstate
17 : Silicates Containing other Anions
10 : Silicates with sulphate, molybdate or tungstate
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 |
|---|---|---|
| Cex | 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 Chessexite
Silky
Transparency:
Translucent
Colour:
White
Cleavage:
Poor/Indistinct
Indistinct parallel to [101]
Indistinct parallel to [101]
Density:
2.21 g/cm3 (Calculated)
Optical Data of Chessexite
Type:
Biaxial (+)
RI values:
nα = 1.456 nβ = 1.460 nγ = 1.480
2V:
Measured: 47° , Calculated: 50°
Max. Birefringence:
δ = 0.024
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
Dispersion:
distinct
Chemistry of Chessexite
Mindat Formula:
(Na,K)4Ca2(Mg,Zn)3Al8(SO4)10(SiO4)2 · 40H2O
Element Weights:
Common Impurities:
Ca
Crystallography of Chessexite
Crystal System:
Orthorhombic
Cell Parameters:
a = 13.70 Å, b = 27.96 Å, c = 9.99 Å
Ratio:
a:b:c = 0.49 : 1 : 0.357
Unit Cell V:
3,826.69 ų (Calculated from Unit Cell)
Z:
2
Morphology:
Euhedral, thin square or rectangular plates.
Comment:
Point Group: n.d.; Space Group: n.d.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 13.91 Å | (100) |
| 3.422 Å | (100) |
| 4.85 Å | (90) |
| 3.982 Å | (60) |
| 3.451 Å | (40) |
| 3.322 Å | (40) |
| 2.908 Å | (30) |
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 Chessexite
General Appearance of Type Material:
euhedral, thin, square or rectangular plates, to 0.03 mm.
Place of Conservation of Type Material:
Natural History Museum, Geneva, Switzerland 435/70
Geological Setting of Type Material:
Coating on fluorite
Associated Minerals at Type Locality:
Synonyms of Chessexite
Other Language Names for Chessexite
Related Minerals - Strunz-mindat Grouping
| 7.DG. | Mathesiusite | K5(UO2)4(SO4)4(VO5) · 4H2O |
| 7.DG.05 | Darapskite | Na3(SO4)(NO3) · H2O |
| 7.DG.10 | Clinoungemachite | (Na, K, Fe, SO4) |
| 7.DG.10 | Humberstonite | Na7K3Mg2(SO4)6(NO3)2 · 6H2O |
| 7.DG.10 | Ungemachite | K3Na8Fe(SO4)6(NO3)2 · 6H2O |
| 7.DG.15 | Chiyokoite | Ca3Si(CO3)[B(OH)4]O (OH)5 · 12H2O |
| 7.DG.15 | Kottenheimite | Ca 3Si(SO4)2(OH)6 · 12H2O |
| 7.DG.15 | Hielscherite | Ca3Si(SO4)(SO3)(OH)6 · 11H2O |
| 7.DG.15 | Jouravskite | Ca3Mn4+(SO4)(CO3)(OH)6 · 12H2O |
| 7.DG.15 | Thaumasite | Ca3(SO4)[Si(OH)6](CO3) · 12H2O |
| 7.DG.15 | Bentorite | Ca6Cr2(SO4)3(OH)12 · 26H2O |
| 7.DG.15 | Carraraite | Ca3(SO4)[Ge(OH)6](CO3) · 12H2O |
| 7.DG.15 | Ettringite | Ca6Al2(SO4)3(OH)12 · 26H2O |
| 7.DG.15 | Birunite | Ca18(SiO3)8.5(CO3)8.5SO4 · 15H2O(?) |
| 7.DG.15 | Siwaqaite | Ca6Al2(CrO4)3(OH)12 · 26H2O |
| 7.DG.15 | Buryatite | Ca3(Si,Fe3+,Al)(SO4)B(OH)4(OH,O)6 · 12H2O |
| 7.DG.15 | Charlesite | Ca6(Al,Si)2(SO4)2[B(OH)4](OH,O)12 · 26H2O |
| 7.DG.15 | Tatarinovite | Ca3Al(SO4)[B(OH)4](OH)6 · 12H2O |
| 7.DG.15 | Imayoshiite | Ca3Al(CO3)[B(OH)4](OH)6 · 12H2O |
| 7.DG.15 | Sturmanite | Ca6Fe3+2(SO4)2.5[B(OH)4](OH)12 · 25H2O |
| 7.DG.20 | Rapidcreekite | Ca2(SO4)(CO3) · 4H2O |
| 7.DG.25 | Tatarskite | Ca6Mg2(SO4)2(CO3)2(OH)4Cl4 · 7H2O |
| 7.DG.30 | Nakauriite | Cu8(SO4)4(CO3)(OH)6 · 48H2O |
| 7.DG.40 | Fuenzalidaite | K6(Na,K)4Na6Mg10(SO4)12(IO3)12 · 12H2O |
| 7.DG.40 | Carlosruizite | K6(Na,K)4Na6Mg10(SeO4)12(IO3)12 · 12H2O |
| 7.DG.45 | 'Chelyabinskite' | (Ca,Mg)3(SO4,CO3)2[Si(OH)6] · 9H2O (?) |
| 7.DG.55 | Ramazzoite | [Mg8Cu12(PO4)(CO3)4(OH)24(H2O)20][(H0.33SO4)3(H2O)36] |
| 7.DG.60 | Witzkeite | Na4K4Ca(NO3)2(SO4)4 · 2H2O |
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 Chessexite
mindat.org URL:
https://www.mindat.org/min-996.html
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Please feel free to link to this page.
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References for Chessexite
Localities for Chessexite
Showing 3 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.
France (TL) | |
| Sarp et al. (1982) |
Iceland | |
| Mitolo et al. (2008) |
USA | |
| Livingston et al. (2005, December) |
Quick NavTopAbout ChessexiteUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography X-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesStrunz-MindatOther InformationInternet Links References Localities Locality List
Maine Mine, Cordesse, Lucenay-l'Evêque, Autun, Saône-et-Loire, Bourgogne-Franche-Comté, France