Chiyokoite
A valid IMA mineral species
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About Chiyokoite
Chiyoko Henmi
Formula:
Ca3Si(CO3)[B(OH)4]O (OH)5 · 12H2O
formerly given as Ca3Si(CO3){[B(OH)4]0.5(AsO3)0.5}(OH)6.12H2O; however, the arsenate(III) anion is not a mandatory constituent
Colour:
Pink to colorless
Lustre:
Vitreous
Specific Gravity:
1.85
Crystal System:
Hexagonal
Member of:
Name:
Named in honor of Chiyoko Henmi (逸見 千代子) (1949–2018), professor in the Department of Earth Science at Okayama University. She made significant contributions to the mineralogy of skarn minerals from the Fuka mine, including the discovery of eight new minerals. The mineral henmilite is also named, in part, in her honor.
Unique Identifiers
Mindat ID:
54035
Long-form identifier:
mindat:1:1:54035:5
IMA Classification of Chiyokoite
Approved
IMA Formula:
Ca3Si(CO3)[B(OH)4]O(OH)5·12H2O
First published:
2020
Approval history:
IMA Dec 2020: revised formula as Ca3SiCO3)B(OH)4]O(OH)5•12H2O.
Type description reference:
Lykova, Inna, Chukanov, Nikita V., Pekov, Igor V., Yapaskurt, Vasiliy O., Pautov, Leonid A., Karpenko, Vladimir Yu., Belakovskiy, Dmitry I., Varlamov, Dmitry A., Britvin, Sergey N., Scheidl, Katharina S. (2020) Chiyokoite, Ca3Si(CO3)[B(OH)4]O(OH)5·12H2O, a new ettringite-group mineral from the Fuka mine, Okayama Prefecture, Japan. The Canadian Mineralogist, 58 (5) 653-662 doi:10.3749/canmin.2000030
Classification of Chiyokoite
7.DG.15
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
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 |
|---|---|---|
| Cyo | 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 Chiyokoite
Vitreous
Transparency:
Transparent
Colour:
Pink to colorless
Streak:
White
Cleavage:
Distinct/Good
{1010} and {0001} good
{1010} and {0001} good
Fracture:
Step-Like
Density:
1.85(1) g/cm3 (Measured) 1.85 g/cm3 (Calculated)
Comment:
Measured by flotation in heavy liquids (bromoform + dimethylformamide)
Optical Data of Chiyokoite
Type:
Uniaxial (-)
RI values:
nω = 1.523(2) nε = 1.492(3)
Max. Birefringence:
δ = 0.031
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 uniaxial interference figure - the conoscopic
(convergent-light, Bertrand-lens-in) view, for a grain cut with the optic axis
centred and vertical. The coloured rings are isochromatics, computed with the
same physics as the Michel-Lévy bar above; the dark cross is the isogyre.
For a genuinely uniaxial mineral viewed this way, that cross stays perfectly stationary if you rotate the stage - unlike a biaxial mineral, where it splits apart on rotation. That invariance is itself the standard diagnostic test for telling uniaxial and biaxial minerals apart at the microscope.
For a genuinely uniaxial mineral viewed this way, that cross stays perfectly stationary if you rotate the stage - unlike a biaxial mineral, where it splits apart on rotation. That invariance is itself the standard diagnostic test for telling uniaxial and biaxial minerals apart at the microscope.
Pleochroism:
Non-pleochroic
Comments:
Rectangular grains have straight extinction, and most of them have negative elongation. Some grains are of hexagonal shape; these are isotropic and show an interference figure perpendicular to the optical axis.
Chemistry of Chiyokoite
Mindat Formula:
Ca3Si(CO3)[B(OH)4]O (OH)5 · 12H2O
formerly given as Ca3Si(CO3){[B(OH)4]0.5(AsO3)0.5}(OH)6.12H2O; however, the arsenate(III) anion is not a mandatory constituent
formerly given as Ca3Si(CO3){[B(OH)4]0.5(AsO3)0.5}(OH)6.12H2O; however, the arsenate(III) anion is not a mandatory constituent
Element Weights:
Crystallography of Chiyokoite
Crystal System:
Hexagonal
Class (H-M):
6 - Pyramidal
Space Group:
P63
Setting:
P63
Cell Parameters:
a = 11.0119(5) Å, c = 10.5252(6) Å
Ratio:
a:c = 1 : 0.956
Unit Cell V:
1105.3 ų
Morphology:
The major forms are the hexagonal prism {1010} and monohedra {0001} and {0001}. Narrow faces of the hexagonal pyramid {h0il} are observed on some crystals.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 9.53 Å | (100) |
| 5.50 Å | (24) |
| 4.618 Å | (11) |
| 3.812 Å | (23) |
| 3.412 Å | (15) |
| 2.726 Å | (14) |
| 2.521 Å | (19) |
| 2.172 Å | (13) |
Reference:
Lykova, Inna, Chukanov, Nikita V., Pekov, Igor V., Yapaskurt, Vasiliy O., Pautov, Leonid A., Karpenko, Vladimir Yu., Belakovskiy, Dmitry I., Varlamov, Dmitry A., Britvin, Sergey N., Scheidl, Katharina S. (2020) Chiyokoite, Ca3Si(CO3)[B(OH)4]O(OH)5·12H2O, a new ettringite-group mineral from the Fuka mine, Okayama Prefecture, Japan. The Canadian Mineralogist, 58 (5) 653-662 doi:10.3749/canmin.2000030
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| High-? alteration and/or metamorphism | |
| 31 : Thermally altered carbonate, phosphate, and iron formations |
Type Occurrence of Chiyokoite
General Appearance of Type Material:
Hexagonal prismatic crystals up to 30 µm long and up to 20 µm thick. Clusters which form friable nests up to 1 cm across.
Place of Conservation of Type Material:
collections of the (1) Fersman Mineralogical Museum, Russian Academy of Sciences, Leninskiy Prospekt 18-2, Moscow 119071, Russia, registration number 5412/1; (2) the Canadian Museum of Nature, 240 McLeod Street, Ottawa, ON K2P 2R1, Canada, catalogue number CMNMC 87294 (cotypes)
Geological Setting of Type Material:
Low-temperature hydrothermally altered, boron-bearing, low-Fe calc-silicate skarn.
Associated Minerals at Type Locality:
Reference:
Lykova, Inna, Chukanov, Nikita V., Pekov, Igor V., Yapaskurt, Vasiliy O., Pautov, Leonid A., Karpenko, Vladimir Yu., Belakovskiy, Dmitry I., Varlamov, Dmitry A., Britvin, Sergey N., Scheidl, Katharina S. (2020) Chiyokoite, Ca3Si(CO3)[B(OH)4]O(OH)5·12H2O, a new ettringite-group mineral from the Fuka mine, Okayama Prefecture, Japan. The Canadian Mineralogist, 58 (5) 653-662 doi:10.3749/canmin.2000030
Other Language Names for Chiyokoite
Dutch:Chiyokoiet
German:Chiyokoit
Relationship of Chiyokoite to other Species
Member of:
Other Members of Ettringite Group:
| Bentorite | Ca6Cr2(SO4)3(OH)12 · 26H2O | Trig. 3m : P31c |
| Buryatite | Ca3(Si,Fe3+,Al)(SO4)B(OH)4(OH,O)6 · 12H2O | Trig. 3m : P31c |
| Carraraite | Ca3(SO4)[Ge(OH)6](CO3) · 12H2O | Hex. |
| Charlesite | Ca6(Al,Si)2(SO4)2[B(OH)4](OH,O)12 · 26H2O | Trig. 3m : P31c |
| Ettringite | Ca6Al2(SO4)3(OH)12 · 26H2O | Trig. 3m : P31c |
| Hielscherite | Ca3Si(SO4)(SO3)(OH)6 · 11H2O | Hex. 6 : P63 |
| Imayoshiite | Ca3Al(CO3)[B(OH)4](OH)6 · 12H2O | Hex. 6/mmm(6/m2/m2/m) : P63/mmc |
| Jouravskite | Ca3Mn4+(SO4)(CO3)(OH)6 · 12H2O | Hex. 6 : P63 |
| Kottenheimite | Ca 3Si(SO4)2(OH)6 · 12H2O | Hex. 6/m : P63/m |
| Micheelsenite | (Ca2Y)Al(PO3OH)(CO3)(OH)6 · 12H2O | Hex. 6 : P63 |
| Siwaqaite | Ca6Al2(CrO4)3(OH)12 · 26H2O | Trig. 3m : P31c |
| Sturmanite | Ca6Fe3+2(SO4)2.5[B(OH)4](OH)12 · 25H2O | Trig. 3m : P31c |
| Tatarinovite | Ca3Al(SO4)[B(OH)4](OH)6 · 12H2O | Hex. 6 : P63 |
| Thaumasite | Ca3(SO4)[Si(OH)6](CO3) · 12H2O | Hex. 6 : P63 |
| 'UM2008-07-CO:AlBCaHSSi' | Ca6(Al,Si)2(CO3,SO4)2[B(OH)4](OH,O)12 · 26H2O | |
| 'Unnamed (possible Mn(IV) analogue of Sturmanite)' | Ca6Mn4+2(SO4)2[B(OH)4](OH)10O2 · nH2O |
Common Associates
Associations Based on Photo Data:
| 6 photos of Chiyokoite associated with Henmilite | Ca2Cu[B(OH)4]2(OH)4 |
| 4 photos of Chiyokoite associated with Calcite | CaCO3 |
| 1 photo of Chiyokoite associated with Bultfonteinite | Ca2(HSiO4)F · H2O |
| 1 photo of Chiyokoite associated with Olshanskyite | Ca2[B3O3(OH)6](OH) · 3H2O |
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 | 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.35 | Chessexite | (Na,K)4Ca2(Mg,Zn)3Al8(SO4)10(SiO4)2 · 40H2O |
| 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 |
Fluorescence of Chiyokoite
Non fluorescent
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 Chiyokoite
mindat.org URL:
https://www.mindat.org/min-54035.html
Please feel free to link to this page.
Please feel free to link to this page.
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External Links:
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References for Chiyokoite
Reference List:
Miyawaki, Ritsuro, Hatert, Frédéric, Pasero, Marco, Mills, Stuart J. (2019) CNMNC Newsletter 52.New minerals and nomenclature modifications approved in 2019. Mineralogical Magazine, 83 (6) 887-893 doi:10.1180/mgm.2019.73
Lykova, Inna, Chukanov, Nikita V., Pekov, Igor V., Yapaskurt, Vasiliy O., Pautov, Leonid A., Karpenko, Vladimir Yu., Belakovskiy, Dmitry I., Varlamov, Dmitry A., Britvin, Sergey N., Scheidl, Katharina S. (2020) Chiyokoite, Ca3Si(CO3)[B(OH)4]O(OH)5·12H2O, a new ettringite-group mineral from the Fuka mine, Okayama Prefecture, Japan. The Canadian Mineralogist, 58 (5) 653-662 doi:10.3749/canmin.2000030
Localities for Chiyokoite
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.
Japan (TL) | |
| Lykova et al. (2019) +1 other reference |
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Fuka mine, Fuka, Bitchū, Takahashi City, Okayama Prefecture, Japan