Kobeite-(Y)
A valid IMA mineral species - grandfathered
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About Kobeite-(Y)
Formula:
(Y,U)(Ti,Nb)2(O,OH)6 (?)
Colour:
Black to dark brown
Lustre:
Vitreous, Resinous
Hardness:
5½
Specific Gravity:
4.60
Crystal System:
Isometric
Member of:
Name:
Originally named simply kobeite for the type locality of Kobe, Kyoto prefecture, Japan (Kobe-mura, Kyoto prefecture - presently Oyama-cho). The suffix was added in 1987 to denote the predominate rare-earth element.
A metamict member of the euxenite group.
Unique Identifiers
Mindat ID:
2232
Long-form identifier:
mindat:1:1:2232:9
GUID
(UUID V4):
(UUID V4):
232e0f6e-67dc-47d1-91c0-745ff9d84c6c
IMA Classification of Kobeite-(Y)
Approved, 'Grandfathered' (first described prior to 1959)
IMA status notes:
Renamed by the IMA
First published:
1950
Classification of Kobeite-(Y)
4.DG.05
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
D : Metal: Oxygen = 1:2 and similar
G : With large (+- medium-sized) cations; chains of edge-sharing octahedra
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
D : Metal: Oxygen = 1:2 and similar
G : With large (+- medium-sized) cations; chains of edge-sharing octahedra
8.3.12.1
8 : MULTIPLE OXIDES CONTAINING NIOBIUM,TANTALUM OR TITANIUM
3 : AB2O6
8 : MULTIPLE OXIDES CONTAINING NIOBIUM,TANTALUM OR TITANIUM
3 : AB2O6
18.4.7
18 : Niobates and Tantalates
4 : Niobates and tantalates containing both U and rare earths
18 : Niobates and Tantalates
4 : Niobates and tantalates containing both U and rare earths
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 |
---|---|---|
Kob-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 Kobeite-(Y)
Vitreous, Resinous
Transparency:
Transparent, Translucent
Colour:
Black to dark brown
Streak:
Reddish brown
Hardness:
5½ on Mohs scale
Tenacity:
Brittle
Parting:
Perpendicular to the length, probably a parting.
Fracture:
Conchoidal
Density:
4.60 g/cm3 (Measured) 4.13 g/cm3 (Calculated)
Optical Data of Kobeite-(Y)
Type:
Isotropic
RI values:
n = 2.205(5)
Birefringence:
Isotropic minerals have no birefringence
Surface Relief:
Very High
Comments:
Coffee-brown to brownish yellow in thin section.
Chemistry of Kobeite-(Y)
Mindat Formula:
(Y,U)(Ti,Nb)2(O,OH)6 (?)
Crystallography of Kobeite-(Y)
Crystal System:
Isometric
Cell Parameters:
a = 5.039(16) Å
Unit Cell V:
127.95 ų (Calculated from Unit Cell)
Z:
1
Comment:
Metamict
X-Ray Powder Diffraction
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
2.89 Å | (100) |
2.506 Å | (40) |
1.776 Å | (80) |
1.514 Å | (70) |
1.154 Å | (30 broad) |
1.126 Å | (30 broad) |
1.027 Å | (20 broad) |
Comments:
Shiraishi pegmatite, Japan. The data are from Hutton (1957). Data collected after heating sample for one hour at 620°C in air.
Geological Environment
Paragenetic Mode(s):
Paragenetic Mode | Earliest Age (Ga) |
---|---|
Near-surface Processes | |
26 : Hadean detrital minerals | |
Stage 4b: Highly evolved igneous rocks | >3.0 |
34 : Complex granite pegmatites |
Type Occurrence of Kobeite-(Y)
General Appearance of Type Material:
Mineral is prismatic in habit and the crystals are grouped in twin-like forms.
Place of Conservation of Type Material:
National Science Museum, Tokyo, Japan (type).
Geological Setting of Type Material:
Granite pegmaitites.
Associated Minerals at Type Locality:
Reference:
Takubo, J., Ukai, Y., Minato, T. (1950) Studies on the minerals containing rare elements (Part II) A new mineral found in Kobe-mura, Kyoto Prefecture, Japan. Chishitsugaku Zasshi: 56: 509-513.
Other Language Names for Kobeite-(Y)
Japanese:河辺石
Relationship of Kobeite-(Y) to other Species
Member of:
Other Members of this group:
Euxenite-(Y) | (Y,Ca,Ce,U,Th)(Nb,Ta,Ti)2O6 | Orth. mmm (2/m 2/m 2/m) : Pbcn |
Fersmite | (Ca,Ce,Na)(Nb,Ta,Ti)2(O,OH,F)6 | Orth. mmm (2/m 2/m 2/m) : Pbcn |
Loranskite-(Y) | (Y,Ce,Ca)ZrTaO6 (?) | |
Tanteuxenite-(Y) | Y(Ta,Nb,Ti)2(O,OH)6 | Orth. mmm (2/m 2/m 2/m) : Pbcn |
Uranopolycrase | (U4+,Y)(Ti,Nb)2O6 | Orth. mmm (2/m 2/m 2/m) : Pbcn |
Yttrocrasite-(Y) | (Y,Th,Ca,U)(Ti,Fe)2(O,OH)6 | Amor. |
Related Minerals - Strunz-mindat Grouping
4.DG.05 | Euxenite-(Y) | (Y,Ca,Ce,U,Th)(Nb,Ta,Ti)2O6 |
4.DG.05 | Fersmite | (Ca,Ce,Na)(Nb,Ta,Ti)2(O,OH,F)6 |
4.DG.05 | Loranskite-(Y) | (Y,Ce,Ca)ZrTaO6 (?) |
4.DG.05 | Tanteuxenite-(Y) | Y(Ta,Nb,Ti)2(O,OH)6 |
4.DG.05 | Uranopolycrase | (U4+,Y)(Ti,Nb)2O6 |
4.DG.05 | Yttrocrasite-(Y) | (Y,Th,Ca,U)(Ti,Fe)2(O,OH)6 |
4.DG.10 | Clinofergusonite-(Y) | YNbO4 |
4.DG.10 | Clinofergusonite-(Nd) | (Nd,Ce)NbO4 |
4.DG.10 | Clinofergusonite-(Ce) | CeNbO4 |
4.DG.10 | Yttrotantalite-(Y) | (Y,U,Fe2+)(Ta,Nb)(O,OH)4 |
4.DG.15 | Foordite | Sn2+Nb2O6 |
4.DG.15 | Thoreaulite | Sn2+Ta2O6 |
4.DG.20 | Raspite | Pb(WO4) |
Other Information
Notes:
Metamict, radioactive.
Health Risks:
Radioactive
Internet Links for Kobeite-(Y)
mindat.org URL:
https://www.mindat.org/min-2232.html
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References for Kobeite-(Y)
Localities for Kobeite-(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.
Austria | |
| Collection of Natural History Museum +3 other references |
Canada | |
| T.S. Ercit - 2002 Rochester Min. ... |
Italy | |
| Bedognè et al. (1993) |
Japan | |
| Yukikazu Ogoshi (2011) |
| Pavel.M. Kartashov (n.d.) |
Alfredo Petrov specimens | |
| Takubo et al. (1950) |
| Alfredo Petrov specimen |
Mexico | |
| Prol-Ledesma et al. (2012) |
New Zealand | |
| Hutton (1957) |
Norway | |
| Åmli (1974) |
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Hataga pegmatite, Hataga, Hiroshima City, Hiroshima Prefecture, Japan