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Yftisite-(Y)

A discredited species name
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About Yftisite-(Y)Hide

Formula:
(Y,Dy,Er)4(Ti,Sn)(SiO4)2O(F,OH)6
Colour:
Light yellow
Lustre:
Resinous
Hardness:
3½ - 4
Name:
The name is derived from its composition: yttrium (Y), fluorine (F), titanium (Ti) and silicon (Si).
Originally reported from El'ozero REE occurrence, Western Keivy Massif, Kola Peninsula, Murmanskaja Oblast', Russia and Verkhnee Espe Massif, Tarbagatai Range, Semipalatinsk Oblysy, Kazakhstan.

A discredited mineral, but apparently valid since a crystal-structure determination was reported (Balko & Bakakin, 1975).

Identical to the later described mieite-(Y).


Unique IdentifiersHide

Mindat ID:
4360
Long-form identifier:
mindat:1:1:4360:7

Similar NamesHide

Vitusite-(Ce)A valid IMA mineral speciesNa3(Ce,La,Nd)(PO4)2

IMA Classification of Yftisite-(Y)Hide

Discredited

Classification of Yftisite-(Y)Hide

9.AG.25

9 : SILICATES (Germanates)
A : Nesosilicates
G : Nesosilicates with additional anions; cations in > [6] +- [6] coordination
52.4.4.3

52 : NESOSILICATES Insular SiO4 Groups and O,OH,F,H2O
4 : Insular SiO4 Groups and O, OH, F, and H2O with cations in [6] and/or >[6] coordination
17.1.20

17 : Silicates Containing other Anions
1 : Silicates with fluoride (not containing Al)

Physical Properties of Yftisite-(Y)Hide

Resinous
Transparency:
Transparent
Colour:
Light yellow
Hardness:
3½ - 4 on Mohs scale
Fracture:
Conchoidal

Optical Data of Yftisite-(Y)Hide

Type:
Biaxial (-)
RI values:
nα = 1.69 nβ = 1.705 nγ = 1.71 - 1.712
Max. Birefringence:
δ = 0.020 - 0.022
Based on recorded range of RI values above.

Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.

Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.

Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.

Surface Relief:
Very High (positive)
Relative to Canada balsam mounting medium (n ≈ 1.537).

This shows the grain boundary and Becke line effect under plane-polarised light, based on the contrast between this mineral's average refractive index and the mounting medium. It does not take into account mineral colouration.
In focus
Interference Figure:
This shows the idealized biaxial acute bisectrix (Bxa) interference figure - the conoscopic view for a grain cut perpendicular to the acute bisectrix, using this mineral's 2V. The two small white dots mark the melatopes - the points where the two optic axes emerge - and are shown only when they fall within the field of view. The coloured bands are isochromatics, and the dark bands are isogyres.

Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.

No measured or calculated 2V is on file for this mineral, so the value used here (64°) is estimated from its recorded refractive indices and optic sign, not from a direct 2V measurement.
Dispersion:
strong

Chemistry of Yftisite-(Y)Hide

Mindat Formula:
(Y,Dy,Er)4(Ti,Sn)(SiO4)2O(F,OH)6
Element Weights:
Element% weight
Y49.554 %
O20.065 %
F15.884 %
Si7.827 %
Ti6.670 %

Calculated from ideal end-member formula.
Y
O
F
Si
Ti

Epitaxial Relationships of Yftisite-(Y)Hide

Epitaxial Minerals:

First Recorded Occurrence of Yftisite-(Y)Hide

Synonyms of Yftisite-(Y)Hide

Other Language Names for Yftisite-(Y)Hide

Common AssociatesHide

Associations Based on Photo Data:
1 photo of Yftisite-(Y) associated with Fergusonite-(Y)YNbO4

Related Minerals - Strunz-mindat GroupingHide

9.AG.Aluminotaipingite-(CeCa)(Ce6Ca3)◻Al(SiO4)3[SiO3(OH)]4F3Trig. 3m : R3c
9.AG.'Ivanyukite-Na-T'Na2Ti4(SiO4)3(OH)O3 · 7H2OTrig. 3m : R3m
9.AG.'Ivanyukite-Na-C'Na2Ti4(SiO4)3(OH)2O2 · 6H2OIso. 43m : P43m
9.AG.EdgrewiteCa9(SiO4)4F2 Mon. 2/m : P21/b
9.AG.02GatedaliteZrMn2+2Mn3+4SiO12Tet. 4/mmm(4/m2/m2/m) : I41/acd
9.AG.05AbswurmbachiteCuMn3+6(SiO4)O8Tet. 4/mmm(4/m2/m2/m) : I41/acd
9.AG.05NeltneriteCaMn3+6(SiO4)O8Tet. 4/mmm(4/m2/m2/m) : I41/acd
9.AG.05SkogbyiteZr(Mg2Mn3+4)SiO12Tet. 4/mmm(4/m2/m2/m) : I41/acd
9.AG.05BrauniteMn2+Mn3+6(SiO4)O8Tet. 4/mmm(4/m2/m2/m) : I41/acd
9.AG.05'Braunite-II'Ca(Mn3+,Fe)14(SiO4)O20Tet. 4/mmm(4/m2/m2/m) : I41/acd
9.AG.10LångbaniteMn2+4Mn3+9Sb5+O16(SiO4)2Trig. 3m : P3m1
9.AG.12Taipingite-(CeCa)(Ce7Ca2)◻Mg(SiO4)3[SiO3(OH)]4F3Trig. 3m : R3c
9.AG.15ŻabińskiiteCa[Al0.5(Ta,Nb)0.5)]O(SiO4)Tric. 1
9.AG.15TitaniteCaTiO(SiO4)Mon. 2/m : P21/b
9.AG.15VanadomalayaiteCaVO(SiO4)Mon. 2/m : B2/b
9.AG.15Natrotitanite(Na0.5Y0.5)TiO(SiO4)Mon. 2/m : B2/b
9.AG.15MalayaiteCaSnO(SiO4)Mon. 2/m
9.AG.20Ferricerite-(LaCa)(La6Ca3)◻Fe3+(SiO4)3(SiO3OH)4(OH)3Trig. 3m : R3c
9.AG.20Aluminocerite-(CeCa)(Ce6Ca3)◻Al(SiO4)3[SiO3(OH)]4(OH)3Trig. 3m : R3c
9.AG.20Cerite-(CeCa)(Ce7Ca2)◻Mg(SiO4)3(SiO3OH)4(OH)3Trig. 3m : R3c
9.AG.20Nipeiite-(Ce)Ce9Fe3+(SiO4)6[SiO3(OH)](OH)3Trig. 3m : R3c
9.AG.25Mieite-(Y)Y4Ti(SiO4)2O[F,(OH)]6Orth. mmm(2/m2/m2/m) : Cmcm
9.AG.25Trimounsite-(Y)Y2Ti2(SiO4)O5Mon. 2/m : P21/b
9.AG.30SitinakiteKNa2Ti4(SiO4)2O5(OH) · 4H2OTet. 4/mmm(4/m2/m2/m) : P42/mcm
9.AG.35KittatinnyiteCa2Mn2Mn(SiO4)2(OH)4 · 9H2OHex.
9.AG.40bParanatisiteNa2Ti(SiO4)OOrth. mmm(2/m2/m2/m) : Pmma
9.AG.40aNatisiteNa2Ti(SiO4)OTet. 4/mmm(4/m2/m2/m)
9.AG.45Törnebohmite-(Ce)Ce2Al(SiO4)2(OH)Mon. 2/m : P21/b
9.AG.45Törnebohmite-(La)La2Al(SiO4)2(OH)
9.AG.50Ivanyukite-NaNa2Ti4(SiO4)3(OH)2O2 · 6H2OTrig. 3m : R3m
9.AG.50Ivanyukite-KK2Ti4(SiO4)3(OH)2O2 · 9H2OIso. 43m : P43m
9.AG.50Ivanyukite-CuCuTi4(SiO4)3(OH)2O2 · 7H2OIso. 43m : P43m
9.AG.50Kuliokite-(Y)Y4Al(SiO4)2(OH)2F5Mon. m
9.AG.50HydroxyledgrewiteCa9(SiO4)4(OH)2 Mon. 2/m : P21/b
9.AG.52Ulfanderssonite-(Ce)(Ce15Ca)Σ16Mg2(SiO4)10(SiO3OH)(OH,F)5Cl3Mon. m : Bm
9.AG.55ChantaliteCaAl2(SiO4)(OH)4Tet. 4/m : I41/a
9.AG.60VuagnatiteCaAl(SiO4)(OH)Orth. 222 : P212121
9.AG.60MozartiteCaMn3+(SiO4)(OH)Orth. 222 : P212121
9.AG.65HatruriteCa3(SiO4)OTrig.
9.AG.70JasmunditeCa11(SiO4)4O2STet. 42m : I4m2
9.AG.75AfwilliteCa3[SiO4][SiO2(OH)2] · 2H2OMon. m : Bb
9.AG.80BultfonteiniteCa2(HSiO4)F · H2OTric. 1 : P1
9.AG.85ZoltaiiteBaV4+2V3+12(SiO4)2O19Trig. 3 : P3
9.AG.90Tranquillityite(Fe2+,Ca)8(Zr,Y)2Ti3(SiO4)3O12Hex.

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.

Internet Links for Yftisite-(Y)Hide

References for Yftisite-(Y)Hide

Localities for Yftisite-(Y)Hide

Showing 5 localities.

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.
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Locality ListHide

- 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.
Japan
 
  • Mie Prefecture
    • Mie District
      • Komono town
        • Yunoyama-onsen
Matsubara et al. (2014) +1 other reference
  • Miyazaki Prefecture
    • Nobeoka City
Minakawa & Adachi (1994)
Kazakhstan (FRL)
 
  • Abai Region
    • Tarbagatai Range
      • Akzhaylyautas Mts (Akzhailyautas Mts; Akjaylautas Mts; Akzhalautas Mts)
Am Min 62 (1977) +1 other reference
Russia (FRL)
 
  • Murmansk Oblast
    • Lovozersky District
      • Keivy Mountains
        • Western Keivy Massif
American Mineralogist (1977) +1 other reference
Sweden
 
  • Stockholm County
    • Vaxholm
      • Resarö
King et al. (1987)
 
and/or  
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