Kobeite-(Y) Mineral Data

Kobeite-(Y) Mineral Data +

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General Kobeite-(Y) Information

Chemical Formula:

(Y,U)(Ti,Nb)2(O,OH)6 (?)

Composition:

Molecular Weight = 319.10 gm

Yttrium 25.08 % Y 31.84 % Y₂O₃

Uranium 7.46 % U 8.46 % UO₂

Titanium 22.51 % Ti 37.55 % TiO₂

Niobium 14.56 % Nb 20.83 % Nb₂O₅

Hydrogen 0.32 % H 2.82 % H₂O

Oxygen 30.08 % O

______ ______

100.00 % 101.50 % = TOTAL OXIDE

Empirical Formula:

Y_0.9U_0.1Ti_1.5Nb_0.5O₅(OH)

Environment:

In granite pegmatites.

IMA Status:

Valid Species (Pre-IMA) 1950

Locality:

Kobe-Mura [presently Oyama-cho], Japan. Link to MinDat.org Location Data.

Name Origin:

Named for the locality.

Kobeite-(Y) Image

Images:

Kobeite-(Y)

Comments: Subparallel aggregate of black, tabular, euhedral kobeite-(Y) crystals in matrix.
Location: Ohro, Kobe, Kyoto, Japan. Scale: Picture size 5 mm.
© Paul M. Schumacher

Kobeite-(Y) Crystallography

Cell Dimensions:

a = 5.021, Z = 1; V = 126.58 Den(Calc)= 4.19

Crystal System:

IsometricSpace Group: Cubic

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 2.89(1), 1.776(0.8), 1.514(0.7),

Physical Properties of Kobeite-(Y)

Cleavage:

None

Color:

Brown, Brownish black, Dark brown, Black.

Density:

4.6

Diaphaniety:

Transparent to Translucent

Fracture:

Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.

Habit:

Metamict - Mineral originally crystalline, now amorphous due to radiation damage.

Habit:

Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).

Habit:

Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite)

Hardness:

5.5 - Knife Blade

Luster:

Vitreous - Resinous

Streak:

reddish brown

Optical Properties of Kobeite-(Y)

Gladstone-Dale:

CI meas= 0.049 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= -0.044 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2876,KPDmeas= 0.262,KC= 0.2756

Optical Data:

Isotropic, n=2.205.

Calculated Properties of Kobeite-(Y)

Electron Density:

r_electron=3.86 gm/cc
note: r_Kobeite-(Y)=4.19 gm/cc.

Fermion Index

Fermion Index = 0.02978
Boson Index = 0.97022

Photoelectric:

PE_Kobeite-(Y)= 242.17 barns/electron
U=PE_Kobeite-(Y) x r_electron= 933.62 barns/cc.

Radioactivity:

GRapi = 585,028.87 (Gamma Ray American Petroleum Institute Units)

Kobeite-(Y) is Radioactive as defined in 49 CFR 173.403. Greater than 70 Bq / gram.

Estimated Maximum U.S. Postal Shipping Size (10 mRem/hr limit, Unshielded 10 cm box) 51.99 ± 13.00 grams of pure Kobeite-(Y) .
Estimated Maximum U.S. Postal Shipping Size (10 mRem/hr limit, Unshielded 100 cm box) 5199.2 ±1299.8 grams of pure Kobeite-(Y) .

**Estimated Radioactivity from Kobeite-(Y)** - strong
Specimen Size Weight/Volume (Sphere) *	Calculated Activity Bequerols (Bq)	Calculated Activity Curies (Ci)	Estimated Activity GR(api)	Estimated Exposure (mRem**)/hr If Held in Hand For One Hour
1000 gm / 7.70 cm	13,352,469	3.61E-04	585,028.87	192.34
100 gm / 3.57 cm	1,335,247	3.61E-05	58,502.89	19.23
10 gm / 1.66 cm	133,525	3.61E-06	5,850.29	1.92
1 gm / 7.70 mm	13,352	3.61E-07	585.03	0.19
0.1 gm / 3.57 mm	1,335	3.61E-08	58.50	0.02
0.01 gm / 1.66 mm	134	3.61E-09	5.85	0.00
0.001 gm / 0.77 mm	13	3.61E-10	0.59	0.00

Weight of pure Kobeite-(Y) in grams (gm) and Calculated Diameter of a Sphere with a Density of 4.19 gm/cc.*
Goverment Estimate of Average Annual Exposure ( 360 mRem) **
Note: 10 microsieverts/hr = 1 mRem/hr **
Max Permissable Adult Dose 50,000 mRem/yr (hands), 15,000 mRem/yr (eyes)
Lethal Dose LD(50) Exposure 400,000 to 500,000 mRem

Kobeite-(Y) Classification

Dana Class:

8.3.12.1 (8)Multiple Oxides with Nb, Ta, and Ti

(8.3)where A (B2O6)

(8.3.12)Dana Group

8.3.12.1 Kobeite-(Y) (Y,U)(Ti,Nb)2(O,OH)6(?) Cubic Cubic

Strunz Class:

IV/D.20-20 IV - Oxides

IV/D - Oxides with metal : oxygen = 1:2 (MO2 and related compounds)

IV/D.20 - Kassite - Lucasite-(Ce) series

IV/D.20-10 Kassite CaTi2O4(OH)2 P 2₁/a 2/m

IV/D.20-20 Kobeite-(Y) (Y,U)(Ti,Nb)2(O,OH)6(?) Cubic Cubic

IV/D.20-30 Lucasite-(Ce) CeTi2(O,OH)6 I2/a 2/m

Other Kobeite-(Y) Information

References:

NAME( AntBidBlaNic3) PHYS. PROP.(AntBidBlaNic3) OPTIC PROP.(AntBidBlaNic3)

See Also:

Links to other databases for Kobeite-(Y) :
1 -Am. Min. Crystal Structure Database 2 -Athena 3 - EUROmin Project 4 -Google Images 5 -Google Scholar 6 -Handbook of Mineralogy (UofA) 7 -MinDAT 8 -MinMax(Deutsch) 9 -MinMax(English) 10 -Mineralienatlas (Deutsch) 11 -QUT Mineral Atlas

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Kobeite-(Y)

(Y,U)(Ti,Nb)2(O,OH)6 (?)
Dana No: 8.3.12.1 Strunz No: IV/D.20-20
Locality:

Notes: