Antigorite Mineral Data

General Antigorite Information

Chemical Formula:

(Mg,Fe++)3Si2O5(OH)4

Composition:

Molecular Weight = 300.77 gm

Magnesium 18.18 % Mg 30.15 % MgO

Iron 13.93 % Fe 17.92 % FeO

Silicon 18.68 % Si 39.95 % SiO₂

Hydrogen 1.34 % H 11.98 % H₂O

Oxygen 47.88 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Mg_2.25Fe²⁺_0.75(Si₂O₅)(OH)₄

Environment:

Common in regional and contact metamorphosed serpentinites

IMA Status:

Valid Species (Pre-IMA) 1840

Locality:

Antigorio, Italy Link to MinDat.org Location Data.

Name Origin:

Named after its locality. From the Latin, serpens - "snake."

Name Pronunciation:

Antigorite + Pronunciation

Synonym:

Bowenite

Jenkinsite

Picrosmine

Protoantigorite

Williamsite

Antigorite Image

Images:

Antigorite

Comments: Yellowish green, fibrous antigorite.
Location: East Broughon, Quebec, Canada. Scale: 22x10 cm.
© Dave Barthelmy

Images:

Antigorite Chromite

Comments: Chromite veins in yellow to green antigorite with picrolite, chromian antigorite and dolomite (polished section).
Location: Wood's Mine, near 'Texas', Little Britain Township, Lancaster County, Pennsylvania, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Antigorite Crystallography

Axial Ratios:

a:b:c =4.7013:1:0.7844

Cell Dimensions:

a = 43.53, b = 9.259, c = 7.263, Z = 16; beta = 91.633° V = 2,926.12 Den(Calc)= 2.73

Crystal System:

Monoclinic - DomaticH-M Symbol (m) Space Group: Cm

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

By Intensity(I/I_o): 2.53(1), 7.29(1), 3.61(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

Capitani G , Mellini M , American Mineralogist , 89 (2004) p.147-158, The modulated crystal structure of antigorite: The m = 17 polysome

View Additional jPOWD Structure files for Antigorite
[1] [2]

Physical Properties of Antigorite

Cleavage:

{001} Good

Color:

Green, Gray, Bluish gray, Brown, Black.

Density:

2.5 - 2.6, Average = 2.54

Diaphaneity:

Translucent to Subopaque

Fracture:

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

Habit:

Massive - Uniformly indistinguishable crystals forming large masses.

Habit:

Platy - Sheet forms (e.g. micas).

Habit:

Scaly - Morphology like fish scales.

Hardness:

3.5-4 - Copper Penny-Fluorite

Luster:

Vitreous - Greasy

Streak:

greenish white

Optical Properties of Antigorite

Gladstone-Dale:

CI meas= -0.017 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.05 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2068,KPDmeas= 0.2214,KC= 0.2178
Ncalc = 1.54 - 1.59

Optical Data:

Biaxial (-), a=1.555-1.567, b=1.56-1.573, g=1.56-1.573, bire=0.0050-0.0060, 2V(Calc)=0, 2V(Meas)=20-50. Dispersion weak, r > v.

Pleochroism (x):

pale greenish yellow.

Pleochroism (y):

light green.

Pleochroism (z):

light green.

Calculated Properties of Antigorite

Electron Density:

Bulk Density (Electron Density)=2.55 gm/cc
note: Specific Gravity of Antigorite =2.55 gm/cc.

Fermion Index:

Fermion Index = 0.03
Boson Index = 0.97

Photoelectric:

PE_Antigorite= 5.20 barns/electron
U=PE_Antigorite x rElectron Density= 13.27 barns/cc.

Radioactivity:

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

Antigorite Classification

Dana Class:

71.01.02a.01 (71)Phyllosilicate Sheets of Six-Membered Rings

(71.01)with 1:1 layers

(71.01.02a)Serpentine group

71.01.02a.01 Antigorite (Mg,Fe)3Si2O5(OH)4 Cm m

Strunz Class:

09.ED.15 09 - SILICATES (Germanates)

09.E - Phyllosilicates

09.ED -Phyllosilicates with kaolinite layers

09.ED.15 Clinochrysotile? Mg3Si2O5(OH)4 Cc, C 2/m Mono

09.ED.15 Berthierine (Fe,Fe,Al,Mg)2-3(Si,Al)2O5(OH)4 Cm m

09.ED.15 Brindleyite (Ni,Mg,Fe)2Al(SiAl)O5(OH)4 C 2 2

09.ED.15 Amesite Mg2Al(SiAl)O5(OH)4 C1 1

09.ED.15 Antigorite (Mg,Fe)3Si2O5(OH)4 Cm m

09.ED.15 Caryopilite (Mn,Mg,Zn,Fe)3(Si,As)2O510(OH,Cl)4 Cm or C 2/m Mono

09.ED.15 Fraipontite (Zn,Al)3(Si,Al)2O5(OH)4 Cm m

09.ED.15 Cronstedtite Fe2Fe(SiFe)O5(OH)4 P 3₁m 3m

09.ED.15 Chrysotile Mg3Si2O5(OH)4 A2/m 2/m

09.ED.15 Nepouite Ni3Si2O5(OH)4 Ccm21 mm2

09.ED.15 Greenalite (Fe,Fe)2-3Si2O5(OH)4 Unk Mono

09.ED.15 Kellyite (Mn,Mg,Al)3(Si,Al)2O5(OH)4 P 6₃ 6

09.ED.15 Maufite? (Mg,Ni)Al4Si3O13•4(H2O)(?) Mono ? Mono

09.ED.15 Lizardite Mg3Si2O5(OH)4 P1 1

09.ED.15 Orthochrysotile? Mg3Si2O5(OH)4 Unk Ortho

09.ED.15 Manandonite Li2Al4[(Si2AlB)O10](OH)8 C1 1

09.ED.15 Pecoraite Ni3Si2O5(OH)4 C 2/m 2/m

09.ED.15 Parachrysotile? Mg3Si2O5(OH)4 Unk Ortho

Other Antigorite Information

References:

NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Heinrich65)

See Also:

Links to other databases for Antigorite :
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 - HyperPhysics
11 - MinDAT
12 - Mineralienatlas (Deutsch)
13 - Online Mineral Museum
14 - QUT Mineral Atlas
15 - Ruff.Info
16 - WWW-MINCRYST

Search for Antigorite using:

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

Visit our Advertisers for Antigorite :

A Bijoux Google Search for Antigorite
Adam's Minerals Google Search for Antigorite
Cape Minerals Google Search for Antigorite
Dakota Matrix Minerals Google Search for Antigorite
Excalibur Mineral Corp. Google Search for Antigorite
Exceptional Minerals Google Search for Antigorite
John Betts Fine Minerals Search for Antigorite
McDougall Minerals Google Search for Antigorite
Mineral News Website Link
Rock and Mineral Shows Google Search for Antigorite
Weinrich Minerals, Inc. Google Search for Antigorite

Ask about Antigorite 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 Antigorite Specimen Label here :

Antigorite

(Mg,Fe++)3Si2O5(OH)4
Dana No: 71.01.02a.01 Strunz No: 09.ED.15
Locality:

Notes: