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Nioboholtite

A valid IMA mineral species
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00262400017272472238403.jpg
Nioboholtite, etc.

Mt. Szklana Mine, Szklary, Gmina Ząbkowice Śląskie, Ząbkowice Śląskie County, Lower Silesian Voivodeship, Poland
00262400017272472238403.jpg
Nioboholtite, etc.

Mt. Szklana Mine, Szklary, Gmina Ząbkowice Śląskie, Ząbkowice Śląskie County, Lower Silesian Voivodeship, Poland
07645930017271951725407.jpg
Nioboholtite, etc.

Mt. Szklana Mine, Szklary, Gmina Ząbkowice Śląskie, Ząbkowice Śląskie County, Lower Silesian Voivodeship, Poland
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About NioboholtiteHide

Formula:
(Nb0.6◻0.4)Al6BSi3O18
Colour:
Creamy-white to brownish-yellow or gray-yellow
Specific Gravity:
3.72 (Calculated)
Crystal System:
Orthorhombic
Name:
For the mineral holtite and its niobium content.
This is Nb-analogue of titanoholtite. Nioboholtite is also the second mineral, after schiavinatoite, with essential Nb and B.


Unique IdentifiersHide

Mindat ID:
43588
Long-form identifier:
mindat:1:1:43588:6

IMA Classification of NioboholtiteHide

IMA status:
Approved
IMA Formula:
(Nb5+0.6◻0.4)Al6BSi3O18
Approval year:
2012

Classification of NioboholtiteHide

Strunz-mindat (2026):
9.AJ.10

9 : SILICATES (Germanates)
A : Nesosilicates
J : Nesosilicates with BO3 triangles and/or B[4], Be[4] tetrahedra, cornersharing with SiO4

Mineral SymbolsHide

As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.

SymbolSourceReference for Standard
NhltIMA–CNMNCWarr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43

Physical Properties of NioboholtiteHide

Transparency:
Translucent
Colour:
Creamy-white to brownish-yellow or gray-yellow
Streak:
White
Density:
3.72 g/cm3 (Calculated)

Optical Data of NioboholtiteHide

Type:
Biaxial (-)
RI values:
nα = 1.740 - 1.747 nβ = 1.76 nγ = 1.76
Max. Birefringence:
δ = 0.013 - 0.020
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 (-0°) is estimated from its recorded refractive indices and optic sign, not from a direct 2V measurement.

Chemistry of NioboholtiteHide

Mindat Formula:
(Nb0.6◻0.4)Al6BSi3O18
Element Weights:
Element% weight
O47.943 %
Al26.951 %
Si14.027 %
Nb9.280 %
B1.800 %

Calculated from ideal end-member formula.
O
Al
Si
Nb
B
Elements listed:
Al, B, Nb, O, Si - search for minerals with similar chemistry
Common Impurities:
Sb,As

Crystallography of NioboholtiteHide

Crystal System:
Orthorhombic
Class (H-M):
mmm(2/m2/m2/m) - Dipyramidal
Space Group:
Pbcm
Cell Parameters:
a = 47.001 Å, b = 11.828 Å, c = 20.243 Å
Ratio:
a:b:c = 3.974 : 1 : 1.711
Unit Cell V:
11,253.65 ų (Calculated from Unit Cell)

X-Ray Powder DiffractionHide

Powder Diffraction Data:
d-spacingIntensity
10.213 Å(67)
5.914 Å(40)
5.861 Å(66)
3.458 Å(63)
3.231 Å(100)
3.068 Å(53)
2.931 Å(65)
2.895 Å(64)
Locality:
Mt. Szklana Mine (Szklary pegmatite), Szklary, Gmina Ząbkowice Śląskie, Ząbkowice Śląskie County, Lower Silesian Voivodeship, Poland
Comments:
From Type Description.

Geological EnvironmentHide

Paragenetic Mode(s):
Paragenetic ModeEarliest Age (Ga)
Stage 4b: Highly evolved igneous rocks>3.0
34 : Complex granite pegmatites

Type Occurrence of NioboholtiteHide

Type Locality:
ⓘ Mt. Szklana Mine (Szklary pegmatite), Szklary, Gmina Ząbkowice Śląskie, Ząbkowice Śląskie County, Lower Silesian Voivodeship, Poland
Place of Conservation of Type Material:
Mineralogical Museum of the University of Wrocław, Wrocław, Poland, catalogue number MMWr IV7615; cotype specimens are deposited in the same Museum, catalogue numbers MMWr IV7616, MMWr IV7617, MMWr IV7618 and MMWr IV7619, and in the collections of the Smi
Geological Setting of Type Material:
Szklary serpentinite massif, c. 60 km south of Wrocław, Lower Silesia, Poland (50º39.068’N 16º49.932’E)
Associated Minerals at Type Locality:
AlluauditeNative AntimonyNative ArsenicBetafite GroupBeusite
Native BismuthCheraliteChlorapatiteChrysoberylColumbite-(Fe)
Columbite-(Mn)DumortieriteErnienickeliteFersmiteFluorapatite
Native GoldGorceixiteHollanditeHoltiteHydroxylapatite
MicroclineMicrolite GroupMitridatiteMonazite-(Ce)Muscovite
NatrophiliteNioboholtiteNontroniteParadocrasitePhosphohedyphane
PlumbogummitePollucitePurpuritePyrochlore GroupQuartz
RanciéiteRomanèchiteSaponiteSpessartineStibarsen
StibiocolumbiteStibiotantaliteTantalite-(Mn)ThorutiteTitanoholtite
UraniniteXenotime-(Y)Zircon

Synonyms of NioboholtiteHide

Other Language Names for NioboholtiteHide

Relationship of Nioboholtite to other SpeciesHide

Member of:
Holtite Group > Dumortierite Supergroup
Other Members of Holtite Group:
Holtite(Ta0.6◻0.4)Al6BSi3O18(O,OH)2.25Orth. mmm(2/m2/m2/m) : Pnma
Titanoholtite(Ti0.75◻0.25)Al6BSi3O18Orth. mmm(2/m2/m2/m) : Pbcm

Common AssociatesHide

Associations Based on Photo Data:
1 photo of Nioboholtite associated with Holtite(Ta0.6◻0.4)Al6BSi3O18(O,OH)2.25
1 photo of Nioboholtite associated with Titanoholtite(Ti0.75◻0.25)Al6BSi3O18

Related Minerals - Strunz-mindat GroupingHide

9.AJ.Hingganite-(Nd)Nd2◻Be2Si2O8(OH)2Mon. 2/m : P21/c
9.AJ.Arrheniusite-(Ce)CaMg[(Ce7Y3)Ca5](SiO4)4(Si2B3AsO18)(BO3)F11Trig. 3m : R3m
9.AJ.05Ominelite(Fe2+,Mg)(Al,Fe3+)3(SiO4)(BO3)O2Orth. mmm(2/m2/m2/m) : Pnma
9.AJ.05Grandidierite(Mg,Fe2+)(Al,Fe3+)3(SiO4)(BO3)O2Orth. mmm(2/m2/m2/m) : Pnma
9.AJ.10DumortieriteAl(Al2O)(Al2O)2(SiO4)3(BO3)Orth. mmm(2/m2/m2/m)
9.AJ.10Titanoholtite(Ti0.75◻0.25)Al6BSi3O18Orth. mmm(2/m2/m2/m) : Pbcm
9.AJ.10Holtite(Ta0.6◻0.4)Al6BSi3O18(O,OH)2.25Orth. mmm(2/m2/m2/m) : Pnma
9.AJ.10MagnesiodumortieriteMg(Al2OH)(Al2O)2(SiO4)3(BO3)Orth. mmm(2/m2/m2/m)
9.AJ.15GarrelsiteBa3NaSi2B7O16(OH)4Mon. 2/m : B2/b
9.AJ.20'Muromontite'near Be2FeY2Si3O12
9.AJ.20Gadolinite-(Nd)Nd2Fe2+Be2O2(SiO4)2Mon. 2/m : P21/c
9.AJ.20DatoliteCaB(SiO4)(OH)Mon. 2/m : P21/c
9.AJ.20Melanocerite-(Ce)(Ce,Ca)5(SiO4,BO4)3(OH,O)Hex.
9.AJ.20Gadolinite-(Ce)(Ce,La,Nd,Y)2Fe2+Be2Si2O10Mon. 2/m
9.AJ.20Gadolinite-(Y)Y2Fe2+Be2Si2O10Mon. 2/m : P21/c
9.AJ.20'Unnamed (OH-analogue of Gadolinite-(Y))'(Y,Ca)2(Fe,◻)Be2Si2O8(OH,O)2Mon. 2/m
9.AJ.20Hingganite-(Ce)(Ce,REE)2(◻,Fe2+)Be2[SiO4]2(OH)2Mon. 2/m : P21/c
9.AJ.20Hingganite-(Y)(Y,REE,Ca)2(◻,Fe2+)Be2[SiO4]2(OH)2Mon. 2/m : P21/c
9.AJ.20Hingganite-(Yb)(Yb,Y,REE)2◻Be2[SiO4]2(OH)2Mon. 2/m : P21/c
9.AJ.20HomiliteCa2(Fe2+,Mg)B2Si2O10Mon. 2/m : P21/c
9.AJ.20'Minasgeraisite-(Y)'(Ca2Y2)◻2(Be2B2)[SiO4]4(OH)4Tric. 1 : P1
9.AJ.20Calcybeborosilite-(Y)(Y,Ca)2(◻,Fe2+)(B,Be)2[SiO4]2(OH,O)2Mon.
9.AJ.25Stillwellite-(La)LaBSiO5Trig. 32 : P3221
9.AJ.25Stillwellite-(Ce)(Ce,La,Ca)BSiO5Trig. 3 : P31
9.AJ.30Cappelenite-(Y)Ba(Y,Ce)6Si3B6O24F2Trig. 3 : P3
9.AJ.35Laptevite-(Ce)Ca6(Fe2+,Mn2+)Y3REE7(SiO4)3(PO4)(B3Si3O18)(BO3)F11Trig. 3m : R3m
9.AJ.35Proshchenkoite-(Y)Ca(Y,REE,Ca,Na,Mn)15Fe2+(P,Si)Si6B3O34F14Trig. 3m : R3m
9.AJ.35Okanoganite-(Y)(Na,Ca)3(Y,Ce)12Si6B2O27F14Trig. 3m : R3m
9.AJ.35Hundholmenite-(Y)(Y,REE,Ca,Na)15(Al,Fe3+)(CaxAs3+1-x)(Si,As5+)Si6B3(O,F)48Trig. 3m : R3m
9.AJ.35Vicanite-(Ce)(Ca,Ce,La,Th)15As5+(As3+0.5,Na0.5)Fe3+Si6B4O40F7Trig. 3m : R3m
9.AJ.40JadariteLiNaSiB3O7(OH)Mon. 2/m

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 NioboholtiteHide

References for NioboholtiteHide

Localities for NioboholtiteHide

Showing 1 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.
Poland (TL)
 
  • Lower Silesian Voivodeship
    • Ząbkowice Śląskie County
      • Gmina Ząbkowice Śląskie
        • Szklary
Mineralogical Magazine +4 other references
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