Iwashiroite-(Y)
A valid IMA mineral species
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About Iwashiroite-(Y)
Formula:
Y(Ta,Nb)O4
Colour:
Dark red-brown, amber brown to brown
Lustre:
Sub-Adamantine, Vitreous
Hardness:
6
Specific Gravity:
7.1 (Calculated)
Crystal System:
Monoclinic
Name:
Iwashiro was an old name for the district, and is still the name of a neighboring town. The suffix/modifier follows the Levinson rule for minerals with essential REE, indicating a predominance of yttrium.
Type Locality:
Polymorph of:
Only one specimen found, in reddish feldspar in pegmatite.
Zoned (U-rich parts are metamict). Also known as a synthetic compound (M'-type YTaO4; Wolten, 1967).
See also formanite-(Y) and yttrotantalite-(Y).
The structure typically consist of TaO6 octahedra and YO8 polyhedra.
Zoned (U-rich parts are metamict). Also known as a synthetic compound (M'-type YTaO4; Wolten, 1967).
See also formanite-(Y) and yttrotantalite-(Y).
The structure typically consist of TaO6 octahedra and YO8 polyhedra.
Unique Identifiers
Mindat ID:
25650
Long-form identifier:
mindat:1:1:25650:8
GUID
(UUID V4):
(UUID V4):
d2610837-6a2a-4bdb-942b-a470af6e4b05
IMA Classification of Iwashiroite-(Y)
Classification of Iwashiroite-(Y)
7.GA.10
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
G : Molybdates, Wolframates and Niobates
A : Without additional anions or H2O
7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
G : Molybdates, Wolframates and Niobates
A : Without additional anions or H2O
Dana 7th ed.:
8.1.2.4
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 |
---|---|---|
Iwa-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 Iwashiroite-(Y)
Sub-Adamantine, Vitreous
Transparency:
Translucent
Colour:
Dark red-brown, amber brown to brown
Streak:
Pale brown
Hardness:
6 on Mohs scale
Cleavage:
Distinct/Good
on {010}, poor on {001}
on {010}, poor on {001}
Density:
7.1 g/cm3 (Calculated)
Optical Data of Iwashiroite-(Y)
Reflectivity:
Wavelength | R1 | R2 | imR1 | imR2 |
---|---|---|---|---|
400nm | 14.4% | 15.3% | 5.2% | 5.2% |
420nm | 14.3% | 14.9% | 4.4% | 4.6% |
440nm | 14.0% | 14.4% | 4.2% | 4.4% |
460nm | 13.9% | 14.2% | 4.1% | 4.3% |
470nm | 13.8% | 14.1% | 4.1% | 4.4% |
480nm | 13.7% | 14.0% | 4.1% | 4.4% |
500nm | 13.7% | 13.9% | 4.1% | 4.4% |
520nm | 13.5% | 13.8% | 4.0% | 4.4% |
540nm | 13.5% | 13.8% | 4.0% | 4.5% |
546nm | 13.6% | 13.8% | 4.0% | 4.5% |
560nm | 13.6% | 13.8% | 4.1% | 4.6% |
580nm | 13.6% | 13.9% | 4.1% | 4.7% |
589nm | 13.6% | 13.9% | 4.2% | 4.8% |
600nm | 13.7% | 13.9% | 4.3% | 4.8% |
620nm | 13.8% | 14.0% | 4.5% | 5.0% |
640nm | 13.7% | 14.0% | 4.6% | 5.1% |
650nm | 13.7% | 14.0% | 4.6% | 5.0% |
660nm | 13.8% | 14.0% | 4.7% | 5.1% |
680nm | 13.9% | 14.1% | 5.0% | 5.3% |
700nm | 14.1% | 14.3% | 5.8% | 5.9% |
Graph shows reflectance levels at different wavelengths (in nm). Top of box is 100%. Peak reflectance is 15.3%.
R1 shown in black, R2 shown in red, imR1 shown in green, imR2 shown in blue
Comments:
Refractive indices could not be measured due to the very small dimensions of the crystals and the association with a metamict substance.
Chemistry of Iwashiroite-(Y)
Mindat Formula:
Y(Ta,Nb)O4
Elements listed:
Common Impurities:
REE,Ti,U
Crystallography of Iwashiroite-(Y)
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P2/b
Setting:
P2/a
Cell Parameters:
a = 5.262 Å, b = 5.451 Å, c = 5.11 Å
β = 95.12°
β = 95.12°
Ratio:
a:b:c = 0.965 : 1 : 0.937
Unit Cell V:
146 ų
Z:
2
Comment:
M'-type YTaO4 modification.
X-Ray Powder Diffraction
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
3.13 Å | (100) |
2.95 Å | (94) |
2.73 Å | (26) |
1.890 Å | (29) |
1.862 Å | (29) |
Comments:
Format: d/Å (I/%) (hkl)
From type description
From type description
Geological Environment
Paragenetic Mode(s):
Paragenetic Mode | Earliest Age (Ga) |
---|---|
Stage 4b: Highly evolved igneous rocks | >3.0 |
34 : Complex granite pegmatites |
Type Occurrence of Iwashiroite-(Y)
General Appearance of Type Material:
Aggregate of small euhedral platy crystals.
Place of Conservation of Type Material:
National Science Museum, Tokyo, Japan, NSM-M28537.
Geological Setting of Type Material:
Yttrium-rich granite pegmatite.
Associated Minerals at Type Locality:
Synonyms of Iwashiroite-(Y)
Other Language Names for Iwashiroite-(Y)
Related Minerals - Strunz-mindat Grouping
7.GA. | Ronpetersonite | BaWO4 |
7.GA.05 | Fergusonite-(Ce) | CeNbO4 · 0.3H2O |
7.GA.05 | Fergusonite-(Nd) | NdNbO4 |
7.GA.05 | Fergusonite-(Y) | YNbO4 |
7.GA.05 | Powellite | Ca(MoO4) |
7.GA.05 | Scheelite | Ca(WO4) |
7.GA.05 | Stolzite | Pb(WO4) |
7.GA.05 | Wulfenite | Pb(MoO4) |
7.GA.05 | Suseinargiuite | NaBi(MoO4)2 |
7.GA.10 | Formanite-(Y) | YTaO4 |
7.GA.15 | Paraniite-(Y) | Ca2Y(AsO4)(WO4)2 |
7.GA.20 | Takanawaite-(Y) | YTaO4 |
Fluorescence of Iwashiroite-(Y)
Not 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 Iwashiroite-(Y)
mindat.org URL:
https://www.mindat.org/min-25650.html
Please feel free to link to this page.
Please feel free to link to this page.
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External Links:
Mineral Dealers:
References for Iwashiroite-(Y)
Reference List:
Wolten, G. M. (1967) The structure of the M'-phase of YTaO4, a third fergusonite polymorph. Acta Crystallographica, 23 (6) 939-944 doi:10.1107/s0365110x67004098
Hori, Hidemichi, Kobayashi, Toshinori, Miyawaki, Ritsuro, Matsubara, Satoshi, Yokoyama, Kazumi, Shimizu, Masaaki (2006) Iwashiroite-(Y), YTaO4, a new mineral from Suishoyama, Kawamata Town, Fukushima Prefecture, Japan. Journal of Mineralogical and Petrological Sciences, 101 (4) 170-177 doi:10.2465/jmps.101.170
Localities for Iwashiroite-(Y)
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).
Struck out - Mineral was erroneously reported from this locality.
Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).
All localities listed without proper references should be considered as questionable.
All localities listed without proper references should be considered as questionable.
Japan (TL) | |
| Hori et al. (2006) |
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Suishoyama pegmatite, Iizaka Village, Kawamata, Date District, Fukushima Prefecture, Japan