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Falcondoite

A valid IMA mineral species
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07920640017271923035928.jpg
Falcondoite, etc.

Loma Peguera deposit, Falcondo Mines, Bonao, Monseñor Nouel Province, Dominican Republic
02001650017271923065961.jpg
Falcondoite, etc.

Loma Peguera deposit, Falcondo Mines, Bonao, Monseñor Nouel Province, Dominican Republic
09811230017271923078867.jpg
Falcondoite, etc.

Falcondo Mines, Bonao, Monseñor Nouel Province, Dominican Republic
07920640017271923035928.jpg
Falcondoite, etc.

Loma Peguera deposit, Falcondo Mines, Bonao, Monseñor Nouel Province, Dominican Republic
02001650017271923065961.jpg
Falcondoite, etc.

Loma Peguera deposit, Falcondo Mines, Bonao, Monseñor Nouel Province, Dominican Republic
09811230017271923078867.jpg
Falcondoite, etc.

Falcondo Mines, Bonao, Monseñor Nouel Province, Dominican Republic
08510200017271923099560.jpg
Falcondoite, etc.

Loma Peguera deposit, Falcondo Mines, Bonao, Monseñor Nouel Province, Dominican Republic
02001650017271923065961.jpg
Falcondoite, etc.

Loma Peguera deposit, Falcondo Mines, Bonao, Monseñor Nouel Province, Dominican Republic
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About FalcondoiteHide

Formula:
(Ni,Mg)4Si6O15(OH)2 · 6H2O
Colour:
whitish-green
Lustre:
Resinous
Hardness:
2 - 3
Specific Gravity:
1.9
Crystal System:
Orthorhombic
Member of:
Sepiolite Group
Name:
Named after the mining company Falconbridge Dominicana C por A. (Falcondo), which mines at the type locality.
A nickel silicate forming friable masses of minute fibers, less than 10 microns in length.
The Ni analogue of sepiolite.


Unique IdentifiersHide

Mindat ID:
1444
Long-form identifier:
mindat:1:1:1444:7

IMA Classification of FalcondoiteHide

IMA status:
Approved
IMA Formula:
Ni4Si6O15(OH)2 · 6H2O
Approval year:
1976
First published:
1976
Type description reference:
Springer, G. (1976) Falcondoite, nickel analogue of sepiolite. The Canadian Mineralogist, 14 (4) 407-409

Classification of FalcondoiteHide

Strunz-mindat (2025):
9.EE.25

9 : SILICATES (Germanates)
E : Phyllosilicates
E : Single tetrahedral nets of 6-membered rings connected by octahedral nets or octahedral bands
Dana 8th ed.:
74.3.1b.2

74 : PHYLLOSILICATES Modulated Layers
3 : Modulated Layers with joined strips
Hey's CIM Ref.:
14.26.6

14 : Silicates not Containing Aluminum
26 : Silicates of Ni

Mineral SymbolsHide

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

Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.

SymbolSourceReference
FcdIMA–CNMNCWarr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43
FcdWarr (2020)Warr, L.N. (2020) Recommended abbreviations for the names of clay minerals and associated phases. Clay Minerals, 55, 261–264 doi:10.1180/clm.2020.30

Physical Properties of FalcondoiteHide

Lustre:
Resinous
Transparency:
Translucent
Colour:
Whitish-green
Hardness:
2 - 3 on Mohs scale
Tenacity:
Brittle
Density:
1.9 g/cm3 (Measured)    2.54 g/cm3 (Calculated)

Optical Data of FalcondoiteHide

Type:
Biaxial
Dispersion:
r < v strong

Chemistry of FalcondoiteHide

Mindat Formula:
(Ni,Mg)4Si6O15(OH)2 · 6H2O
Element Weights:
Element% weight
O46.854 %
Ni29.893 %
Si21.456 %
H1.797 %

Calculated from ideal end-member formula.
Elements listed:
H, Mg, Ni, O, Si - search for minerals with similar chemistry
Common Impurities:
Al,Cr,Fe

Crystallography of FalcondoiteHide

Crystal System:
Orthorhombic
Cell Parameters:
a = 13.5 Å, b = 26.9 Å, c = 5.24 Å
Ratio:
a:b:c = 0.502 : 1 : 0.195
Unit Cell V:
1902.91 ų
Z:
4
Comment:
Point Group: n.d.; : Space Group: n.d.

X-Ray Powder DiffractionHide

Powder Diffraction Data:
d-spacingIntensity
12.2 Å(100)
3.33 Å(30)
3.19 Å(25)
2.62 Å(30)
2.58 Å(35)
2.44 Å(30)
2.39 Å(20)
Locality:
Loma Peguera deposit, Falcondo Mines, Bonao, Monseñor Nouel Province, Dominican Republic
Reference:
Springer, G. (1976) Falcondoite, nickel analogue of sepiolite. The Canadian Mineralogist, 14 (4) 407-409

Geological EnvironmentHide

Paragenetic Mode(s):
Paragenetic ModeEarliest Age (Ga)
Stage 3b: Earth’s earliest hydrosphere>4.45
13 : Hadean serpentinization
Stage 7: Great Oxidation Event<2.4
47a : [Near-surface hydration of prior minerals]

Type Occurrence of FalcondoiteHide

Type Locality:
ⓘ Loma Peguera deposit, Falcondo Mines, Bonao, Monseñor Nouel Province, Dominican Republic
General Appearance of Type Material:
Slightly schistose, friable masses of minute fibrous particles, less than 10 μm in length.
Place of Conservation of Type Material:
Royal Ontario Museum, Toronto, Ontario, Canada, M34324.
Geological Setting of Type Material:
In garnierite veins cutting a laterite, associated with a serpentinized harzbergite massif.
Associated Minerals at Type Locality:
QuartzSepioliteTalc
Reference:
Springer, G. (1976) Falcondoite, nickel analogue of sepiolite. The Canadian Mineralogist, 14 (4) 407-409

Synonyms of FalcondoiteHide

Other Language Names for FalcondoiteHide

Relationship of Falcondoite to other SpeciesHide

Member of:
Sepiolite Group
Other Members of Sepiolite Group:
Ferrisepiolite(Fe3+,Fe2+,Mg)4((Si,Fe3+)6O15)(O,OH)2 · 6H2OOrth. mmm (2/m 2/m 2/m)
LoughliniteNa2Mg3Si6O16 · 8H2OOrth. mmm (2/m 2/m 2/m)
SepioliteMg4(Si6O15)(OH)2 · 6H2OOrth. mmm (2/m 2/m 2/m) : Pnna

Common AssociatesHide

Associated Minerals Based on Photo Data:
6 photos of Falcondoite associated with WillemseiteNi3Si4O10(OH)2
1 photo of Falcondoite associated with Serpentinite
1 photo of Falcondoite associated with NickelineNiAs
1 photo of Falcondoite associated with GalenaPbS
1 photo of Falcondoite associated with AntigoriteMg3(Si2O5)(OH)4
1 photo of Falcondoite associated with NullaginiteNi2(CO3)(OH)2

Related Minerals - Strunz-mindat GroupingHide

9.EE.CairncrossiteSr2Ca7-xNa2x(Si4O10)4(OH)2(H2O)15-xTric. 1 : P1
9.EE.05BementiteMn7Si6O15(OH)8Mon.
9.EE.07InnsbruckiteMn33(Si2O5)14(OH)38Mon. m : Bm
9.EE.10BrokenhilliteMn8Si6O15(OH)10Hex. 6mm : P63mc
9.EE.10Mcgillite(Mn,Fe)8Si6O15(OH)8Cl2Mon. 2/m : B2/m
9.EE.10FriedeliteMn2+8Si6O15(OH,Cl)10Mon. 2/m : B2/m
9.EE.10Pyrosmalite-(Mn)Mn2+8Si6O15(OH,Cl)10Trig. 3m (3 2/m) : P3m1
9.EE.10Pyrosmalite-(Fe)Fe2+8Si6O15(OH,Cl)10Trig. 3m (3 2/m) : P3m1
9.EE.15Nelenite(Mn,Fe)16(Si12O30)(OH)14[As3+3O6(OH)3]Trig. 3m (3 2/m) : R3m
9.EE.15SchalleriteMn2+16As3Si12O36(OH)17Trig. 3m : P3m1
9.EE.20Palygorskite◻Al2Mg2◻2Si8O20(OH)2(H2O)4 · 4H2OMon. 2/m : B2/m
9.EE.20YofortieriteMn2+Mn2+2Mn2+2◻2Si8O20(OH)2(H2O)4 · 4H2OMon. 2/m : B2/m
9.EE.20WindhoekiteFe3+(Fe3+1.67◻0.33)Ca2◻2Si8O20(OH)2(H2O)4(OH)2 · 6H2OMon. 2/m : B2/m
9.EE.20Windmountainite◻Fe3+2Mg2◻2Si8O20(OH)2(H2O)4 · 4H2OMon. 2/m : B2/m
9.EE.20IkorskyiteKMn3+(Si4O10) · 3H2OMon. 2/m : P21/b
9.EE.20TuperssuatsiaiteFe3+Fe3+2(Na◻)◻2Si8O20(OH)2(H2O)4 · 2H2OMon. 2/m : B2/m
9.EE.20Unnamed (Na-Ca-Fe-Silicate-Hydrate)NaCa(Fe2+,Al,Mn)5[Si8O19(OH)](OH)7 · 5H2OTric. 1 : P1
9.EE.25SepioliteMg4(Si6O15)(OH)2 · 6H2OOrth. mmm (2/m 2/m 2/m) : Pnna
9.EE.25LoughliniteNa2Mg3Si6O16 · 8H2OOrth. mmm (2/m 2/m 2/m)
9.EE.25Kalifersite(K,Na)5Fe3+7Si20O50(OH)6 · 12H2OTric. 1 : P1
9.EE.30OrlymaniteCa4Mn3Si8O20(OH)6 · 2H2OHex.
9.EE.30TungusiteCa4Fe2Si6O15(OH)6Tric. 1 : P1
9.EE.30GyroliteNaCa16Si23AlO60(OH)8 · 14H2OTric. 1 : P1
9.EE.35Reyerite(Na,K)2Ca14(Si,Al)24O58(OH)8 · 6H2OTrig. 3 : P3
9.EE.35KodamaiteNa3(Ca5Na)Si16O36(OH)4F2 · (14-x)H2O Tric. 1 : P1
9.EE.35Truscottite(Ca,Mn)14Si24O58(OH)8 · 2H2OTrig.
9.EE.40NatrosiliteNa2Si2O5Mon. 2/m : P21/b
9.EE.45MakatiteNa2Si4O8(OH)2 · 4H2OMon. 2/m : P21/b
9.EE.50VarennesiteNa8Mn2Si10O25(OH,Cl)2 · 12H2OOrth. mmm (2/m 2/m 2/m) : Cmcm
9.EE.55RaiteMn2+Mn2+2Na2(◻1.75Ti0.25)Si8O20(OH)2(H2O)4 · Na(H2O)6Orth. 2 2 2 : C2 2 2
9.EE.60IntersiliteNa6Mn2+Ti[Si10O24(OH)](OH)3 · 4H2OMon.
9.EE.65ZakharoviteNa4Mn5Si10O24(OH)6 · 6H2OTrig. 3m
9.EE.65ShafranovskiteNa3K2(Mn,Fe,Na)4[Si9(O,OH)27](OH)2 · nH2OTrig. 3m : P3 1c
9.EE.70ZeophylliteCa13Si10O28(OH)2F8 · 6H2OTrig. 3 : R3
9.EE.75Minehillite(K,Na)2-3Ca28Zn4Al4Si40O112(OH)16Hex.
9.EE.80Fedorite(Na,K)2-3(Ca4Na3)Si16O38(OH,F)2 · 3.5H2OTric. 1 : P1
9.EE.80Martinite(Na,◻,Ca)12Ca4(Si,S,B)14B2O38(OH,Cl)2F2 · 4H2OTric. 1 : P1
9.EE.80EllingseniteNa5Ca6Si18O38(OH)13 · 6H2OTric. 1 : P1
9.EE.85Lalondeite(Na,Ca)6(Ca,Na)3Si16O38(F,OH)2 · 3H2OTric. 1 : P1

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 FalcondoiteHide

References for FalcondoiteHide

Localities for FalcondoiteHide

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 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.
Australia
 
  • Tasmania
    • Waratah-Wynyard municipality
      • Heazlewood district
Bottrill et al. (2008)
Dominican Republic
 
  • Monseñor Nouel Province
    • Bonao
Villanova-de-Benavent et al. (2014)
Springer (1976)
Indonesia
 
  • South Sulawesi Province
    • East Luwu Regency
      • Sorowako
Sufriadin et al. (2012)
Kazakhstan
 
  • Aktobe Region
    • Kargaly District
      • Kempirsay massif
Korobkin et al. (2022)
Korobkin et al. (2022)
Slovakia
 
  • Košice Region
    • Rožňava District
e-rocks.com (n.d.) +2 other references
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