Falcondoite Mineral Data

General Falcondoite Information

Chemical Formula:

(Ni,Mg)4Si6O15(OH)2•6(H2O)

Composition:

Molecular Weight = 750.99 gm

Magnesium 3.24 % Mg 5.37 % MgO

Silicon 22.44 % Si 48.00 % SiO₂

Nickel 23.45 % Ni 29.84 % NiO

Hydrogen 1.88 % H 16.79 % H₂O

Oxygen 49.00 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Ni₃MgSi₆O₁₅(OH)₂•6(H₂O)

Environment:

Laterite deposits. Nickel analog of sepiolite.

IMA Status:

Approved IMA 1976

Locality:

Loma Peruera laterite deposit at Bonao, Dominican Republic. Link to MinDat.org Location Data.

Name Origin:

Named for the contraction of FALCONbridge DOminica C. Por A., the mining company at the type locality.

Name Pronunciation:

Falcondoite + Pronunciation

Synonym:

Garnierite

Genthite

Falcondoite Image

Images:

Falcondoite

Comments: Solid mass of lime green falcondoite.
Location: Riddle, Douglas County, Oregon. USA. Scale: 4 cm.
© John Veevaert

Falcondoite Crystallography

Axial Ratios:

a:b:c =0.5018:1:0.1947

Cell Dimensions:

a = 13.5, b = 26.9, c = 5.24, Z = 4; V = 1,902.91 Den(Calc)= 2.62

Crystal System:

Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: Pncn

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 12.2(1), 2.44(0.3), 3.33(0.3),2.62(0.3), 2.53(0.3), 3.19(0.2), 2.26(0.2), 2.39(0.2),

Physical Properties of Falcondoite

Cleavage:

{???} Distinct

Color:

Green, Yellowish green.

Density:

2.54

Diaphaneity:

Translucent

Fracture:

Friable - The crumbly disintegration of earthy materials or highly fractured minerals.

Habit:

Fibrous - Crystals made up of fibers.

Habit:

Microscopic Crystals - Crystals visible only with microscopes.

Hardness:

2-3 - Gypsum-Calcite

Luminescence:

Non-fluorescent.

Luster:

Resinous

Magnetism:

Nonmagnetic

Streak:

white

Optical Properties of Falcondoite

Gladstone-Dale:

CI meas= 0.017 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.047 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2099,KPDmeas= 0.2165,KC= 0.2202
Ncalc = 1.56 - 1.58

Optical Data:

Biaxial (?), b=1.55

Calculated Properties of Falcondoite

Electron Density:

Bulk Density (Electron Density)=2.56 gm/cc
note: Specific Gravity of Falcondoite =2.54 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Falcondoite= 10.03 barns/electron
U=PE_Falcondoite x rElectron Density= 25.64 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Falcondoite is Not Radioactive

Falcondoite Classification

Dana Class:

74.03.01b.02 (74)Phyllosilicate Modulated Layers

(74.03)with joined strips

(74.03.01b)Palygorskite-sepiolite group (Sepiolite subgroup)

74.03.01b.01 Sepiolite Mg4Si6O15(OH)2•6(H2O) Pnan 2/m 2/m 2/m

74.03.01b.02 Falcondoite (Ni,Mg)4Si6O15(OH)2•6(H2O) Pncn 2/m 2/m 2/m

74.03.01b.03 Loughlinite Na2Mg3Si6O16•8(H2O) Unk Ortho

Strunz Class:

09.EE.25 09 - SILICATES (Germanates)

09.E - Phyllosilicates

09.EE -Single tetrahedral nets of 6-membered rings

09.EE.25 Falcondoite (Ni,Mg)4Si6O15(OH)2•6(H2O) Pncn 2/m 2/m 2/m

09.EE.25 Loughlinite Na2Mg3Si6O16•8(H2O) Unk Ortho

09.EE.25 Kalifersite! (K,Na)5Fe7Si20O50(OH)6•12(H2O) P1 1

09.EE.25 Sepiolite Mg4Si6O15(OH)2•6(H2O) Pnan 2/m 2/m 2/m

Other Falcondoite Information

References:

NAME( Dana8) PHYS. PROP.(Dana8) OPTIC PROP.(Dana8)

See Also:

Links to other databases for Falcondoite :
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

Search for Falcondoite using:

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

Visit our Advertisers for Falcondoite :

Ask about Falcondoite 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 Falcondoite Specimen Label here :

Falcondoite

(Ni,Mg)4Si6O15(OH)2•6(H2O)
Dana No: 74.03.01b.02 Strunz No: 09.EE.25
Locality:

Notes:

Dakota Matrix
Excalibur Minerals
Exceptional Minerals
Hudson Insitute
John Betts Fine Minerals
Mc Dougall Minerals
Mineral News
Rock and Mineral Shows
Weinrich Minerals, Inc.