Ishikawaite Mineral Data

General Ishikawaite Information

Chemical Formula:

(U,Fe,Y,Ca)(Nb,Ta)O4 (?)

Composition:

Molecular Weight = 294.45 gm

Calcium 1.36 % Ca 1.90 % CaO

Yttrium 6.04 % Y 7.67 % Y₂O₃

Uranium 24.25 % U 27.51 % UO₂

Tantalum 15.36 % Ta 18.76 % Ta₂O₅

Niobium 23.66 % Nb 33.85 % Nb₂O₅

Iron 7.59 % Fe 9.76 % FeO

Oxygen 21.73 % O

______ ______

100.00 % 99.46 % = TOTAL OXIDE

Empirical Formula:

U_0.3Fe²⁺_0.4Y_0.2Ca_0.1Nb_0.75Ta_0.25O₄

Environment:

In pegmatites.

IMA Status:

Valid Species (Pre-IMA) 1922

Locality:

Ishikawa, Ivaki Province, Japan. Link to MinDat.org Location Data.

Name Origin:

Named after its locality.

Name Pronunciation:

Ishikawaite + Pronunciation

Ishikawaite Image

Images:

Ishikawaite

Comments: Blocky, metamict crystals of ishikawaite.
Location: Spinelli Quarry (Spinelli prospect), South Glastonbury, Hartford Co., Connecticut, USA. Scale: 15x15x10 mm.
© John Betts - Fine Minerals

Ishikawaite Crystallography

Crystal System:

OrthorhombicSpace Group: Unk

Physical Properties of Ishikawaite

Cleavage:

None

Color:

Black.

Density:

6.2 - 6.4, Average = 6.3

Diaphaneity:

Opaque

Fracture:

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

Habit:

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

Hardness:

5-6 - Between Apatite and Orthoclase

Luster:

Resinous

Streak:

dark brown

Optical Properties of Ishikawaite

Optical Data:

NCalc= 2.15 - from Gladstone-Dale relationship (KC = 0.1819) where Ncalc=Dmeas*KC+1

Calculated Properties of Ishikawaite

Electron Density:

Bulk Density (Electron Density)=5.51 gm/cc
note: Specific Gravity of Ishikawaite =6.30 gm/cc.

Fermion Index:

Fermion Index = 0.003495602
Boson Index = 0.996504398

Photoelectric:

PE_Ishikawaite= 858.78 barns/electron
U=PE_Ishikawaite x r_electron=4,733.22 barns/cc.

Radioactivity:

GRapi = 1,808,443.99 (Gamma Ray American Petroleum Institute Units)
Concentration of Ishikawaite per GRapi unit = 552.96 (PPB)

Ishikawaite 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) 16.82 ± 4.20 grams of pure Ishikawaite .
Estimated Maximum U.S. Postal Shipping Size (10 mRem/hr limit, Unshielded 100 cm box) 1681.9 ±420.48 grams of pure Ishikawaite .

**Estimated Radioactivity from Ishikawaite** - very strong
Specimen Size Weight/Volume (Sphere) *	Calculated Activity Becquerels (Bq)	Calculated Activity Curies (Ci)	Estimated Activity GR(api)	Estimated Exposure (mRem**)/hr If Held in Hand For One Hour
1000 gm / 6.72 cm	43,410,145	1.17E-03	1,808,443.99	594.56
100 gm / 3.12 cm	4,341,015	1.17E-04	180,844.40	59.46
10 gm / 1.45 cm	434,101	1.17E-05	18,084.44	5.95
1 gm / 6.72 mm	43,410	1.17E-06	1,808.44	0.59
0.1 gm / 3.12 mm	4,341	1.17E-07	180.84	0.06
0.01 gm / 1.45 mm	434	1.17E-08	18.08	0.01
0.001 gm / 0.67 mm	43	1.17E-09	1.81	0.00

Weight of pure Ishikawaite in grams (gm) and Calculated Diameter of a Sphere with a Density of 6.30 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

Ishikawaite Classification

Dana Class:

08.01.04.01 (08)Multiple Oxides with Nb, Ta, and Ti

(08.01)where A BO4

(08.01.04)Dana Group

08.01.04.01 Ishikawaite (U,Fe,Y,Ca)(Nb,Ta)O4(?) Unk Ortho

Strunz Class:

04.DB.25 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate

04.D - Metal:Oxygen = 1:2 and similar

04.DB -With medium-sized cations; chains of edge-sharing octahedra

04.DB.25 Ixiolite (Ta,Nb,Sn,Mn,Fe)O2 P 2/c 2/m

04.DB.25 Ishikawaite (U,Fe,Y,Ca)(Nb,Ta)O4(?) Unk Ortho

04.DB.25 Srilankite (Ti,Zr)O2 P bcn 2/m 2/m 2/m

04.DB.25 Samarskite-(Y) (Y,Fe,U)(Nb,Ta)5O4 P bcn 2/m 2/m 2/m

04.DB.25 Samarskite-(Yb)! (Yb,Y,REE,U,Th,Ca,Fe)(Nb,Ta,Ti)O4 P 2/c 2/m

04.DB.25 Yttrocolumbite-(Y) (Y,U,Fe)(Nb,Ta)O4 Unk Ortho

Other Ishikawaite Information

References:

NAME( Ford32) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Ishikawaite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - GeoScienceWorld
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (MinSocAm)
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info
15 - Uranium Minerals

Search for Ishikawaite using:

[AOL] [Bing] [Dog Pile] [GeoScienceWorld] [HotBot] [Ixquick] [Lycos] [MAMMA] [Scirus] [Teoma] [WebCrawler] [Wikipedia] [YAHOO]

Visit our Advertisers for Ishikawaite :

A Bijoux Google Search for Ishikawaite
Adam's Minerals Google Search for Ishikawaite
Cape Minerals Google Search for Ishikawaite
Dakota Matrix Minerals Google Search for Ishikawaite
Excalibur Mineral Corp. Google Search for Ishikawaite
Exceptional Minerals Google Search for Ishikawaite
John Betts Fine Minerals Search for Ishikawaite
McDougall Minerals Google Search for Ishikawaite
Mineral News Website Link
Rock and Mineral Shows Google Search for Ishikawaite
Weinrich Minerals, Inc. Google Search for Ishikawaite

Ask about Ishikawaite here :
Ask-A-Mineralogist from the Mineralogical Society of America
Mindat.org's Discussion Groups
Original Rockhounds Discussion Group
Rockhounds Discussion Group on Yahoo Groups
Mineral Discussion Forum from Fabre Minerals - also available in Español

Print or Cut-and-Paste your Ishikawaite Specimen Label here :

Ishikawaite

(U,Fe,Y,Ca)(Nb,Ta)O4 (?)
Dana No: 08.01.04.01 Strunz No: 04.DB.25
Locality:

Notes: