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About IshikawaiteHide

Sub-Adamantine, Vitreous, Sub-Vitreous, Resinous, Waxy
5 - 6
Specific Gravity:
6.2 - 6.4
Crystal System:
Originally described as YNbO4 in 1922 by Yuji Shibata and Kenjiro Kimura for the type locality Ishikawa pegmatite district, Fukushima Prefecture, Japan. Redefined by Hanson et al. (1999) as (U,Fe)NbO4. (Mineral is metamict; published data on XRD pattern and cell parameters are for heated material, with no guarantee that the structure restored was the original one.)
Ishikawaite is sometimes coated by brown to red brown surface alterations. May partially or completely be metamict.

Classification of IshikawaiteHide

Approved, 'Grandfathered' (first described prior to 1959)
First Published:

4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
D : Metal: Oxygen = 1:2 and similar
B : With medium-sized cations; chains of edge-sharing octahedra

1 : ABO4

18 : Niobates and Tantalates
4 : Niobates and tantalates containing both U and rare earths

Physical Properties of IshikawaiteHide

Sub-Adamantine, Vitreous, Sub-Vitreous, Resinous, Waxy
Translucent, Opaque
Broken surfaces are generally vitreous to sub-adamantine. Thin splinters may show smoky brown translucency.
Dark brown; black
5 - 6 on Mohs scale
Hardness Data:
None Observed
6.2 - 6.4 g/cm3 (Measured)    

Chemical Properties of IshikawaiteHide

IMA Formula:
Common Impurities:

Crystallography of IshikawaiteHide

Crystal System:
Cell Parameters:
a = 5.562 Å, b = 9.934 Å, c = 5.243 Å
β = 93.9°
a:b:c = 0.56 : 1 : 0.528
Unit Cell V:
289.02 ų (Calculated from Unit Cell)
Black rod-like to somewhat bladed crystals {100}. Anhedral masses
usually metamict

Type Occurrence of IshikawaiteHide

General Appearance of Type Material:
Prismatic orthorhombic-appearing black crystals.
Geological Setting of Type Material:
Associated Minerals at Type Locality:

Other Language Names for IshikawaiteHide


Relationship of Ishikawaite to other SpeciesHide

Other Members of this group:
Samarskite-(Y)(Y,Fe3+,Fe2+,U,Th,Ca)2(Nb,Ta)2O8Orth. mmm (2/m 2/m 2/m) : Pbcn
Samarskite-(Yb)(Yb,Y,Fe3+,Fe2+,U,Th,Ca)2(Nb,Ta)2O8Mon. 2/m : P2/b
SrilankiteZrTi2O6Orth. mmm (2/m 2/m 2/m) : Pbcn
Chemically related to group(s):

Common AssociatesHide

Associated Minerals Based on Photo Data:
Columbite-(Fe)6 photos of Ishikawaite associated with Columbite-(Fe) on mindat.org.
Corundum2 photos of Ishikawaite associated with Corundum on mindat.org.
Microcline2 photos of Ishikawaite associated with Microcline on mindat.org.
Monazite-(Ce)1 photo of Ishikawaite associated with Monazite-(Ce) on mindat.org.
Biotite1 photo of Ishikawaite associated with Biotite on mindat.org.

Related Minerals - Nickel-Strunz GroupingHide

4.DB.05ArgutiteGeO2Tet. 4/mmm (4/m 2/m 2/m) : P42/mnm
4.DB.05CassiteriteSnO2Tet. 4/mmm (4/m 2/m 2/m) : P42/mnm
4.DB.05PlattneritePbO2Tet. 4/mmm (4/m 2/m 2/m)
4.DB.05PyrolusiteMn4+O2Tet. 4/mmm (4/m 2/m 2/m) : P42/mnm
4.DB.05RutileTiO2Tet. 4/mmm (4/m 2/m 2/m) : P42/mnm
4.DB.10ByströmiteMgSb2O6Tet. 4/mmm (4/m 2/m 2/m) : P4/nmm
4.DB.10Tapiolite-(Fe)(Fe,Mn)(Ta,Nb)2O6Tet. 4/mmm (4/m 2/m 2/m) : P42/mnm
4.DB.10Tapiolite-(Mn)(Mn,Fe)(Ta,Nb)2O6Tet. 4/mmm (4/m 2/m 2/m) : P42/mnm
4.DB.15bAkhtenskiteε-Mn4+O2Hex. 6/mmm (6/m 2/m 2/m) : P63/mmc
4.DB.15aRamsdelliteMn4+O2Orth. mmm (2/m 2/m 2/m)
4.DB.25Samarskite-(Y)(Y,Fe3+,Fe2+,U,Th,Ca)2(Nb,Ta)2O8Orth. mmm (2/m 2/m 2/m) : Pbcn
4.DB.25SrilankiteZrTi2O6Orth. mmm (2/m 2/m 2/m) : Pbcn
4.DB.25Samarskite-(Yb)(Yb,Y,Fe3+,Fe2+,U,Th,Ca)2(Nb,Ta)2O8Mon. 2/m : P2/b
4.DB.30FerberiteFeWO4Mon. 2/m : P2/b
4.DB.30HübneriteMnWO4Mon. 2/m : P2/b
4.DB.30Sanmartinite(Zn,Fe)WO4Mon. 2/m : P21/b
4.DB.30HeftetjerniteScTaO4Mon. 2/m
4.DB.30HuanzalaiteMgWO4Mon. 2/m : P2/b
4.DB.35Columbite-(Fe)Fe2+Nb2O6Orth. mmm (2/m 2/m 2/m) : Pbcn
4.DB.35Tantalite-(Fe)Fe2+Ta2O6Orth. mmm (2/m 2/m 2/m) : Pbcn
4.DB.35Columbite-(Mn)Mn2+Nb2O6Orth. mmm (2/m 2/m 2/m) : Pbcn
4.DB.35Tantalite-(Mn)Mn2+Ta2O6Orth. mmm (2/m 2/m 2/m) : Pbcn
4.DB.35Tantalite-(Mg)(Mg,Fe2+)(Ta,Nb)2O6Orth. mmm (2/m 2/m 2/m)
4.DB.50Carmichaelite(Ti,Cr,Fe)[O2-x(OH)x]Mon. 2/m : P21/b
4.DB.55AlumotantiteAlTaO4Orth. mmm (2/m 2/m 2/m) : Pbcn

Related Minerals - Hey's Chemical Index of Minerals GroupingHide

18.4.1Uranpyrochlore (of Hogarth 1977)(Ca,U,Ce)2(Nb,Ti,Ta)2O6(OH,F)Iso.
18.4.5Euxenite-(Y)(Y,Ca,Ce,U,Th)(Nb,Ta,Ti)2O6Orth. mmm (2/m 2/m 2/m)
18.4.7Kobeite-(Y)(REE,Fe,U)3 Zr(Ti,Nb)3 O12
18.4.8Polycrase-(Y)Y(Ti,Nb)2(O,OH)6Orth. mmm (2/m 2/m 2/m)
18.4.9Yttropyrochlore (of Hogarth 1977)A2Nb2(O,OH)6Z
18.4.10Calciobetafite (of Mazzi & Munno)(Ca,Na)2(Nb,Ti)2(O,OH)7
18.4.11Yttrobetafite (of Hogarth 1977)A2-mD2X6-wZ1-n
18.4.12Samarskite-(Y)(Y,Fe3+,Fe2+,U,Th,Ca)2(Nb,Ta)2O8Orth. mmm (2/m 2/m 2/m) : Pbcn

Fluorescence of IshikawaiteHide

Not fluorescent in UV

Other InformationHide

Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

References for IshikawaiteHide

Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Shibata, Y. and Kimura, K. (1922) Ishikawaite, a new Mineral from Iwaki Province. Journal of the Chemical Society of Japan: 43: 301, 648.
Kimura, K. (1922). Ishikawaite; a new Mineral from Ishikawa, Iwaki. Journal of the Geological Society of Tokyo: 29: 316-20 (in Japanese).
Ōhashi, R. (1924). Journal of the Geological Society, Tokyo: 31: 166.
Palache, C., Berman, H. & Frondel, C. (1944): The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana Yale University 1837-1892, Volume I: Elements, Sulfides, Sulfosalts, Oxides. John Wiley and Sons, Inc., New York. 7th edition, revised and enlarged: 766.
Hanson, S. L., Simmons, W. B., and Falster, A. U. (1995) Ishikawaite, Polycrase, or “Samarskite” in Maine Pegmatites?. Rochester. Min. Symp., Prog. and Abs. 22:14-15.
Hanson, S. L., Simmons, W. B., Falster, A. U., Foord E. E., Litche F. E. (1999) Proposed Nomenclature for Samarskite Group Minerals: New Data on Ishikawaite and Calciosamarskite. Mineralogical Magazine: 63: 27-36. (Abstract in American Mineralogist: 84: 1467)

Internet Links for IshikawaiteHide

Localities for IshikawaiteHide

This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.

Locality ListHide

- This locality has map coordinates listed. - This locality has estimated coordinates. ⓘ - Click for 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 (eg from pseudomorphs.)

All localities listed without proper references should be considered as questionable.
Hanson, S. L., Simmons, W. B., Falster, A. U., Foord E. E., Litche F. E. (1999) Proposed Nomenclature for Samarskite Group Minerals: New Data on Ishikawaite and Calciosamarskite. Mineralogical Magazine: 63: 27-3
  • South Australia
    • Flinders Ranges
      • North Flinders Ranges
        • Arkaroola Region (Arkaroola Wilderness Sanctuary; Arkaroola Station)
          • Mt Painter area
Brugger, J., Meisser, N., Etschmann, B., Ansermet, S., & Pring, A. (2011). Paulscherrerite from the Number 2 Workings, Mount Painter Inlier, Northern Flinders Ranges, South Australia:“Dehydrated schoepite” is a mineral after all. American Mineralogist, 96(2-3), 229-240.
  • British Columbia
    • Revelstoke Mining Division
      • Revelstoke
DIXON,A., CEMPIREK, J. & GROAT, L.A. (2014) Mineralogy and geochemistry of pegmatites on Mount Begbie, British Columbia. Canadian Mineralogist 52, 129-164.
  • Sichuan
    • Panzhihua
      • Miyi Co.
Zhang Peishan, Yang Zhuming, Tao Kejie, and Yang Xueming (1996): "Mineralogy and Geology of Rare Earths in China", Science Press (Beijing), 226 pp.
  • Xinjiang
    • Yili Hasake Autonomous Prefecture (Ili Kazakh Autonomous Prefecture)
      • Aletai Prefecture (Altay Prefecture)
        • Fuyun Co. (Koktokay Co.)
          • Ayoubulake pegmatite field
Rubo Zhang and Fengming Han (1983): Acta Mineralogica Sinica 3(4), 313-317
Czech Republic
  • South Moravian Region
    • Tišnov
      • Drahonín
Škoda, R., Novák, M.: Akcesorické Nb-Ta-Ti minerály z pegmatitu v uranovém dole Drahonín, strážecké moldanubikum. Acta Musei Moraviae, Scientiae geologicae, 2004, roč. 89, s. 55 - 66.
  • Red Sea
    • Eastern Desert
      • Sikait-Zabara region
Yehia H. Dawood (2011) Mineral Chemistry and Genesis of Uranyl Minerals Associated with Psammitic Gneisses, Abu Rusheid Area, South Eastern Desert of Egypt. JKAU: Earth Sci., Vol. 21, No. 1, pp: 137-169; Raslan, M. F., & Ali, M. A. (2011). Mineralogy and mineral chemistry of rare-metal pegmatites at Abu Rusheid granitic gneisses, South Eastern Desert, Egypt. Geologija, 54(2), 205-222.
  • Occitanie
    • Hautes-Pyrénées
      • La Barthe-de-Neste
        • Avezac-Prat-Lahitte
MONCHOUX P., FONTAN F., DE PARSEVAL P., MARTIN R. F., WANG R. C. (2006) - Igneous albitite dikes in orogenic lherzolithes, Western Pyrénées, France: A possible source for corundum and alkali feldspar xenocrysts in basaltic terranes. I. Mineralogical Asssociations. The Canadian Mineralogist, Vol. 44, pp. 817-842.
Japan (TL)
  • Fukushima
Min Mag 63 (1999), 27.
      • Ishikawa town (Ishikawa-machi)
Alfredo Petrov collection (ex- Bill Pinch collection)
Alfredo Petrov collection
  • Lower Silesia
    • Dzierżoniów District
      • Piława Górna (Ober Peilau; Gnadenfrei)
PIECZKA et al. 2010: Nb-Ta minerals in pegmatites in the DSS mine at Piława Górna, Góry Sowie Block, southwestern Poland. Mineralogia - Special Papers, 37.
Szuszkiewicz, A., Szełęg, E., Pieczka, A., Ilnicki, S., Nejbert, K., Turniak, K., ... & Michałowski, P. (2013) The Julianna pegmatite vein system at the Piława Górna Mine, Góry Sowie Block, SW Poland–preliminary data on geology and descriptive mineralogy. Geological Quarterly, 2013, 57 (3): 000–000
  • Chelyabinsk Oblast
Yu.S. Kobyashev data
Pavel M. Kartashov data
  • Colorado
    • Jefferson Co.
      • South Platte Pegmatite District
Simmons W B, Hanson S H, Falster A U (2006) Samarskite-(Yb): a new species of the samarskite group from the Little Patsy pegmatite, Jefferson County, Colorado, The Canadian Mineralogist 44, 1119-1125
  • Connecticut
    • Hartford Co.
      • Glastonbury
Hanson, S. L., Jarnot, B. M., Falster, A. U., Simmons, W. B., Nizamoff, J. W.: (2003) "Nb-Ta-Ti Oxide Minerals from Two Pegmatites of the Middletown Area, Connecticut," abstract in "Contributed Papers in Specimen Mineralogy, Part 2, 30th Rochester Mineralogical Symposium", Rocks & Minerals, Vol. 79, No. 4, p. 255.
    • Middlesex Co.
      • Portland
Hanson, S., Jarnot, B. M., Falster, A. U., Simmons, W. B., and Nizamoff, J. W., 2003, Nb-Ta-Ti Oxide Minerals from Two Pegmatites of the Middletown Area, Connecticut, Program with Abstracts, v.30, p. 11.; Hanson, S. L., Jarnot, B. M., Falster, A. U., Simmons, W. B., Nizamoff, J. W.: (2003) "Nb-Ta-Ti Oxide Minerals from Two Pegmatites of the Middletown Area, Connecticut," Rochester Mineral Symposium Abstracts, p. 11-12.
  • Maine
    • Sagadahoc Co.
      • Topsham
Canadian Mineralogist Vol. 36, pp.601-608
King & Foord, 1994. Mineralogy of Maine, V. 1.; King and Foord, 2000, Addenda to Volume 1, Mineralogy of Maine, v. 2.
"Maine Mineral Localities, 3rd Ed." by Thompson, W.B., et.al., 1998
King, V. and Foord, E., 1994, Mineralogy of Maine, volume 1; King, V. and Foord, E., 2000, Mineralogy of Maine.
King & Foord, 1994. Mineralogy of Maine, V. 1.; King and Foord, 2000, Addenda to Volume 1, Mineralogy of Maine, v. 2.
King & Foord, 1994. Mineralogy of Maine, V. 1.; King and Foord, 2000, Addenda to Volume 1, Mineralogy of Maine, v. 2.
King, V. and Foord,E., 1994, 2000, Mineralogy of Maine.
  • New Hampshire
    • Carroll Co.
      • Wakefield
Rocks & Min. 80:246 (2005)
Mineral and/or Locality  
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