Chloritoid Mineral Data

Chloritoid Mineral Data

General Chloritoid Information

Chemical Formula:

(Fe++,Mg,Mn)2Al4Si2O10(OH)4

Composition:

Molecular Weight = 484.71 gm

Magnesium 3.01 % Mg 4.99 % MgO

Manganese 2.27 % Mn 2.93 % MnO

Aluminum 22.27 % Al 42.07 % Al₂O₃

Iron 13.83 % Fe 17.79 % FeO

Silicon 11.59 % Si 24.79 % SiO₂

Hydrogen 0.83 % H 7.43 % H₂O

Oxygen 46.21 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Fe²⁺_1.2Mg_0.6Mn²⁺_0.2Al₄Si₂O₁₀(OH)₄

Environment:

Metamorphic phyllites, schists and marbles.

IMA Status:

Valid Species (Pre-IMA) 1837

Locality:

Saas and Lukmanier, Switzerland. Link to MinDat.org Location Data.

Name Origin:

Named after its resemblance to chlorite minerals.

Synonym:

Sismondine(Mg)

Chloritoid Image

Images:

Chloritoid Paragonite

Comments: Grayish crystalline inclusion of chloritoid in white, massive paragonite.
Location: Drandorf Fundgrube Mine, Bockau, Schwarzenberg District, Erzgebirge, Saxony, Germany. Scale: Picture size 4 mm.
© Thomas Witzke / Abraxas-Verlag

Chloritoid Crystallography

Axial Ratios:

a:b:c =1.7335:1:1.6715

Cell Dimensions:

a = 9.5, b = 5.48, c = 9.16, Z = 2; alpha = 96.88°, beta = 101.8°, gamma = 90.03° V = 463.43 Den(Calc)= 3.47

Crystal System:

Triclinic - PinacoidalH-M Symbol ( 1) Space Group: P1

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

By Intensity(I/I_o): 4.47(1), 2.46(0.9), 2.97(0.8),

Crystal Structure:

Mouse
drag1 - LMB Manipulate Structure
drag2 - RMB Resize/Rotate
Keyboard
S - Stereo Pair on/off
H - Help Screen
I - Data Info
A - Atoms On/Off
P - Polyhedra On/Off
B - Bonds On/Off
Help on Above

Hanscom R , American Mineralogist , 65 (1980) p.534-539, The structure of triclinic chloritoid and chloritoid polymorphism

View Additional jPOWD Structure files for Chloritoid
[1] [2] [3]

Physical Properties of Chloritoid

Cleavage:

[???] Imperfect

Color:

Green gray, Green black, Grayish black, Dark green, Dark gray.

Density:

3.52 - 3.57, Average = 3.54

Diaphaniety:

Transparent to translucent

Fracture:

Brittle - Generally displayed by glasses and most non-metallic minerals.

Habit:

Foliated - Two dimensional platy forms.

Habit:

Massive - Uniformly indistinguishable crystals forming large masses.

Hardness:

6.5 - Pyrite

Luminescence:

Non-fluorescent.

Luster:

Pearly

Streak:

colorless green gray

Optical Properties of Chloritoid

Gladstone-Dale:

CI meas= 0.038 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= 0.018 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2094,KPDmeas= 0.2049,KC= 0.2131

Optical Data:

Biaxial (+), a=1.713-1.73, b=1.719-1.734, g=1.723-1.74, bire=0.0100, 2V(Calc)=78-80, 2V(Meas)=36-89. Dispersion r > v.

Pleochroism (x):

greenish gray, olive green, colorless, or greenish blue.

Pleochroism (y):

bluish gray, indigo, or bluish green.

Pleochroism (z):

colorless, greenish yellow, yellow, or pale greenish brown.

Calculated Properties of Chloritoid

Electron Density:

r_electron=3.43 gm/cc
note: r_Chloritoid=3.47 gm/cc.

Fermion Index

Fermion Index = 0.01157
Boson Index = 0.98843

Photoelectric:

PE_Chloritoid= 5.82 barns/electron
U=PE_Chloritoid x r_electron= 19.95 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Chloritoid is Not Radioactive

Chloritoid Classification

Dana Class:

52.3.3.1 (52)Nesosilicate Insular SiO4 Groups and O, OH, F, and H2O

(52.3)with cations in [6] coordination only

(52.3.3)Chloritoid group

52.3.3.1 Chloritoid (Fe,Mg,Mn)2Al4Si2O10(OH)4 P1 1

52.3.3.2 Magnesiochloritoid MgAl2SiO5(OH)2 C 2/c 2/m

52.3.3.3 Ottrelite (Mn,Fe,Mg)2Al4Si2O10(OH)4 C 2/c 2/m

52.3.3.4 Carboirite-VIII Fe(Al,Ge)2O[(Ge,Si)O4](OH)2 C1 1

Strunz Class:

VIII/B.24-20 VIII - Silicates

VIII/B - Nesosubsilicates, with anions unfamiliar to tetraheders, cationes with coordinationnumber between [8] and [12]

VIII/B.24 - Magnesiochloritoid - Ottrelite series

VIII/B.24-10 Magnesiochloritoid MgAl2SiO5(OH)2 C 2/c 2/m

VIII/B.24-20 Chloritoid (Fe,Mg,Mn)2Al4Si2O10(OH)4 P1 1

VIII/B.24-30 Ottrelite (Mn,Fe,Mg)2Al4Si2O10(OH)4 C 2/c 2/m

Other Chloritoid Information

References:

NAME( Duda&Rejl90) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Heinrich65)

Search for Chloritoid using:

[ALTAVISTA] [AOL] [About.com] [All-The-Web] [HotBot] [Ixquick] [LookSmart] [MAMMA] [MSN.COM] [Netscape] [Teoma] [Wikipedia] [YAHOO]

Visit our Advertisers for Chloritoid :
AA Mineral Specimens
A-Rocks Auction
Adams Minerals
B and L Minerals
Dakota Matrix
Dan Weinrich Fine Minerals
Dan Weinrich Auctions
e-Rocks Auctions
Excalibur Minerals
Exceptional Minerals
Fabre Minerals
Greenside Minerals
John Betts Fine Minerals
Masons Minerals
Mineral News
Mineral of the Month Club
MineralsWeb Fine Minerals
Minernet.it
Rockshop.cz Kalat Fine Minerals
T G Fine Minerals
Wrights Rock Shop

Translate Chloritoid Mineral Data :

Ask about Chloritoid 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 Chloritoid Specimen Label here :

Chloritoid

(Fe++,Mg,Mn)2Al4Si2O10(OH)4
Dana No: 52.3.3.1 Strunz No: VIII/B.24-20
Locality:

Notes: