Pecoraite Mineral Data

General Pecoraite Information

Chemical Formula:

Ni3Si2O5(OH)4

Composition:

Molecular Weight = 380.27 gm

Silicon 14.77 % Si 31.60 % SiO₂

Nickel 46.30 % Ni 58.92 % NiO

Hydrogen 1.06 % H 9.48 % H₂O

Oxygen 37.87 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Ni₃SI₂O₅(OH)₄

Environment:

Formed by weathering of Ni-Fe meteorite fragments in a desert environment.

IMA Status:

Approved IMA 1969

Locality:

In the Wolf Creek meteorite. Link to MinDat.org Location Data.

Name Origin:

Named for William Thomas Pecora (1913-1972), Director of the U.S. Geological Survey, geologist and student of nickel silicate deposits.

Name Pronunciation:

Pecoraite + Pronunciation

Synonym:

Chrysotile - (Ni bearing)

Pecoraite Image

Images:

Pecoraite

Comments: Dark green massive pecoraite in matrix.
Location: Nullagin, Western Australia, Australia. Scale: Specimen Size 2x2.5 cm.
© Diederik Visser

Pecoraite Crystallography

Axial Ratios:

a:b:c =0.5742:1:1.6048

Cell Dimensions:

a = 5.26, b = 9.16, c = 14.7, Z = 4; beta = 92° V = 707.84 Den(Calc)= 3.57

Crystal System:

Monoclinic - PrismaticH-M Symbol (2/m) Space Group: C 2/m

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

By Intensity(I/I_o): 7.43(1), 1.529(0.8), 3.66(0.8),

Physical Properties of Pecoraite

Color:

Dark green.

Density:

3.84 - 3.084, Average = 3.46

Diaphaneity:

Translucent

Hardness:

2.5 - Finger Nail

Streak:

light green

Optical Properties of Pecoraite

Gladstone-Dale:

CI meas= 0.173 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= 0.198 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1618,KPDmeas= 0.1669,KC= 0.2017
Ncalc = 1.62 - 1.77

Optical Data:

Biaxial (+/-), a=1.565, b=1.565-1.603, g=1.565-1.603, bire=0.0000-0.0380, 2V(Calc)=0, 2V(Meas)=0.

Calculated Properties of Pecoraite

Electron Density:

Bulk Density (Electron Density)=3.42 gm/cc
note: Specific Gravity of Pecoraite =3.46 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Pecoraite= 18.77 barns/electron
U=PE_Pecoraite x rElectron Density= 64.27 barns/cc.

Radioactivity:

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

Pecoraite Classification

Dana Class:

71.01.02d.04 (71)Phyllosilicate Sheets of Six-Membered Rings

(71.01)with 1:1 layers

(71.01.02d)Serpentine group (Chrysotile subgroup)

71.01.02d.00 Chrysotile! Mg3Si2O5(OH)4 A2/m 2/m

71.01.02d.01 Clinochrysotile? Mg3Si2O5(OH)4 Cc, C 2/m Mono

71.01.02d.02 Orthochrysotile? Mg3Si2O5(OH)4 Unk Ortho

71.01.02d.03 Parachrysotile? Mg3Si2O5(OH)4 Unk Ortho

71.01.02d.04 Pecoraite Ni3Si2O5(OH)4 C 2/m 2/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 Pecoraite Information

References:

NAME( AntBidBlaNic2) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Pecoraite :
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 Pecoraite using:

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

Visit our Advertisers for Pecoraite :

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

Ask about Pecoraite 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 Pecoraite Specimen Label here :

Pecoraite

Ni3Si2O5(OH)4
Dana No: 71.01.02d.04 Strunz No: 09.ED.15
Locality:

Notes: