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Miyawakiite-(Y)
A valid IMA mineral species
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Formula:
◻Y4Fe2(Si8O20)(CO3)4(H2O)3
Colour:
pale–yellow
Lustre:
Vitreous
Hardness:
3 - 4
Specific Gravity:
2.95 (Calculated)
Crystal System:
Tetragonal
Name:
in honor of Dr. Ritsuro Miyawaki (b. 1959)—mineralogist, crystallographer, and director of the Department of Geology and Paleontology at the National Museum of Nature and Science, Japan—for his outstanding contributions to descriptive mineralogy and crystallography. He has contributed to the description of more than forty new mineral species, with REE–bearing minerals making up one–third of them.
Unique combination of elements (at the upload time).
Unique Identifiers
Mindat ID:
471110
Long-form identifier:
mindat:1:1:471110:6
IMA Classification of Miyawakiite-(Y)
Approved
IMA Formula:
◻Y4Fe2+2(Si8O20)(CO3)4(H2O)3
Approval year:
2024
Type description reference:
Nishio-Hamane, Daisuke; Momma, Koichi; Shimobayashi, Norimasa; Ohnishi, Masayuki; Kobayashi, Toshinori (2024) Miyawakiite-(Y), □Y4Fe2(Si8O20)(CO3)4(H2O)3, a new mineral from Suishoyama, Kawamata Town, Fukushima Prefecture, Japan. Journal of Mineralogical and Petrological Sciences, 119. 023 doi:10.2465/jmps.240722
Classification of Miyawakiite-(Y)
9.EA.
9 : SILICATES (Germanates)
E : Phyllosilicates
A : Single nets of tetrahedra with 4-, 5-, (6-), and 8-membered rings
9 : SILICATES (Germanates)
E : Phyllosilicates
A : Single nets of tetrahedra with 4-, 5-, (6-), and 8-membered rings
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 |
|---|---|---|
| Myw-Y | 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 Miyawakiite-(Y)
Vitreous
Transparency:
Transparent
Colour:
Pale–yellow
Streak:
White
Hardness:
3 - 4 on Mohs scale
Tenacity:
Brittle
Density:
2.95 g/cm3 (Calculated)
Optical Data of Miyawakiite-(Y)
Type:
Uniaxial (+)
RI values:
nω = 1.593(3) nε = 1.654(2)
Max. Birefringence:
δ = 0.061
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 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.
Dispersion:
weak
Pleochroism:
Visible
Comments:
O = colorless and E = pale yellow.
Chemistry of Miyawakiite-(Y)
Mindat Formula:
◻Y4Fe2(Si8O20)(CO3)4(H2O)3
Element Weights:
Crystallography of Miyawakiite-(Y)
Crystal System:
Tetragonal
Class (H-M):
4/mmm(4/m2/m2/m) - Ditetragonal Dipyramidal
Space Group:
I4/mcm
Setting:
I4/mcm
Cell Parameters:
a = 17.53637(9) Å, c = 9.55702(8) Å
Ratio:
a:c = 1 : 0.545
Unit Cell V:
2,939.02 ų (Calculated from Unit Cell)
Z:
4
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 12.338 Å | (67) |
| 4.750 Å | (100) |
| 3.431 Å | (68) |
| 3.243 Å | (28) |
| 2.903 Å | (42) |
| 2.783 Å | (36) |
| 2.472 Å | (35) |
| 2.186 Å | (40) |
Reference:
Nishio-Hamane, Daisuke; Momma, Koichi; Shimobayashi, Norimasa; Ohnishi, Masayuki; Kobayashi, Toshinori (2024) Miyawakiite-(Y), □Y4Fe2(Si8O20)(CO3)4(H2O)3, a new mineral from Suishoyama, Kawamata Town, Fukushima Prefecture, Japan. Journal of Mineralogical and Petrological Sciences, 119. 023 doi:10.2465/jmps.240722
Type Occurrence of Miyawakiite-(Y)
General Appearance of Type Material:
tiny crystals of granular, plate–like, or columnar shape up to 0.8 mm
Place of Conservation of Type Material:
Type material is deposited in the collections of the National Museum of Nature and Science, Tsukuba, Ibaraki 305-0005, Japan, specimen number NSM-M51975
Geological Setting of Type Material:
granitic pegmatite
Associated Minerals at Type Locality:
Reference:
Nishio-Hamane, Daisuke; Momma, Koichi; Shimobayashi, Norimasa; Ohnishi, Masayuki; Kobayashi, Toshinori (2024) Miyawakiite-(Y), □Y4Fe2(Si8O20)(CO3)4(H2O)3, a new mineral from Suishoyama, Kawamata Town, Fukushima Prefecture, Japan. Journal of Mineralogical and Petrological Sciences, 119. 023 doi:10.2465/jmps.240722
Synonyms of Miyawakiite-(Y)
Other Language Names for Miyawakiite-(Y)
Dutch:Miyawakiiet-(Y)
German:Miyawakiit-(Y)
Related Minerals - Strunz-mindat Grouping
| 9.EA. | Hydroxymcglassonite-(K) | KSr4Si8O20(OH) · 8H2O |
| 9.EA. | Bussyite-(Y) | (Y,REE,Ca)3(Na,Ca)6MnSi9Be5(O,OH,F)34 |
| 9.EA. | Hydroxyapophyllite-(NH4) | (NH4)Ca4(Si8O20)(OH)(H2O)8 |
| 9.EA. | Fluorapophyllite-(NH4) | NH4Ca4(Si8O20)F · 8H2O |
| 9.EA.05 | Gillespite | BaFe2+Si4O10 |
| 9.EA.05 | Cuprorivaite | CaCuSi4O10 |
| 9.EA.05 | Wesselsite | SrCuSi4O10 |
| 9.EA.05 | Effenbergerite | BaCuSi4O10 |
| 9.EA.07 | Fluorapophyllite-(Cs) | CsCa4(Si8O20)F · 8H2O |
| 9.EA.10 | Ekanite | Ca2ThSi8O20 |
| 9.EA.15 | Fluorapophyllite-(Na) | NaCa4(Si8O20)F · 8H2O |
| 9.EA.15 | Fluorapophyllite-(K) | KCa4(Si8O20)(F,OH) · 8H2O |
| 9.EA.15 | Hydroxyapophyllite-(K) | KCa4(Si8O20)(OH,F) · 8H2O |
| 9.EA.20 | Magadiite | Na2Si14O29 · 11H2O |
| 9.EA.25 | Dalyite | K2ZrSi6O15 |
| 9.EA.25 | Davanite | K2TiSi6O15 |
| 9.EA.30 | Sazhinite-(La) | Na3La[Si6O15] · 2H2O |
| 9.EA.30 | Sazhinite-(Ce) | Na3CeSi6O15 · 2H2O |
| 9.EA.35 | Armstrongite | CaZr[Si6O15] · 3H2O |
| 9.EA.40 | Okenite | Ca10Si18O46 · 18H2O |
| 9.EA.45 | Perettiite-(Y) | Y2Mn4FeSi2B8O24 |
| 9.EA.45 | Nekoite | Ca3Si6O15 · 7H2O |
| 9.EA.45 | Badakhshanite-(Y) | Y2Mn4Al(Si2B7BeO24) |
| 9.EA.47 | Shlykovite | KCa[Si4O9(OH)] · 3H2O |
| 9.EA.50 | Diegogattaite | Na2CaCu2Si8O20 · H2O |
| 9.EA.50 | Cavansite | Ca(VO)Si4O10 · 4H2O |
| 9.EA.52 | Yangite | PbMnSi3O8 · H2O |
| 9.EA.55 | Pentagonite | Ca(VO)Si4O10 · 4H2O |
| 9.EA.60 | Penkvilksite | Na4Ti2Si8O22 · 4H2O |
| 9.EA.60 | Tumchaite | Na2Zr(Si4O11) · 2H2O |
| 9.EA.65 | Nabesite | Na2BeSi4O10 · 4H2O |
| 9.EA.70 | Ajoite | (K,Na)Cu7AlSi9O24(OH)6 · 3H2O |
| 9.EA.75 | Zeravshanite | Na2Cs4Zr3[Si18O45]*2H2O |
| 9.EA.80 | Bussyite-(Ce) | (Ce,REE)3(Na,H2O)6MnSi9Be5(O,OH)30F4 |
| 9.EA.85 | Plumbophyllite | Pb2Si4O10 · H2O |
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 Miyawakiite-(Y)
mindat.org URL:
https://www.mindat.org/min-471110.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 Miyawakiite-(Y)
Reference List:
Nishio-Hamane, Daisuke; Momma, Koichi; Shimobayashi, Norimasa; Mills, Stuart J.; Ohnishi, Masayuki; Kobayashi, Toshinori (2024) Miyawakiite-(Y), IMA 2024-003, in IMA Commission on New Minerals, Nomenclature and Classification (CNMNC). Mineralogical Magazine, 88 (2). 203-209 doi:10.1180/mgm.2024.5
Nishio-Hamane, Daisuke; Momma, Koichi; Shimobayashi, Norimasa; Ohnishi, Masayuki; Kobayashi, Toshinori (2024) Miyawakiite-(Y), □Y4Fe2(Si8O20)(CO3)4(H2O)3, a new mineral from Suishoyama, Kawamata Town, Fukushima Prefecture, Japan. Journal of Mineralogical and Petrological Sciences, 119. 023 doi:10.2465/jmps.240722
Localities for Miyawakiite-(Y)
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) | |
| Nishio-Hamane et al. (2024) +1 other reference |
