Volkonskoite Mineral Data
General Volkonskoite Information
Chemical Formula:
Ca0.3(Cr+++,Mg,Fe+++)2(Si,Al)4O10(OH)2•4(H2O)
Composition:
Molecular Weight = 475.69 gm
Calcium 0.84 % Ca 1.18 % CaO
Magnesium 4.60 % Mg 7.63 % MgO
Aluminum 2.84 % Al 5.36 % Al2 O3
Chromium 13.12 % Cr 19.17 % Cr2 O3
Iron 3.52 % Fe 5.04 % Fe2 O3
Silicon 20.66 % Si 44.21 % SiO2
Hydrogen 1.95 % H 17.42 % H2 O
Oxygen 52.47 % O
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
Ca0.1 Mg0.1 Cr1.2 Mg0.8 Fe3+ 0.3 Si3.5 Al0.5 O10 (OH)2 �3.6(H2 O)
Environment:
Epignetic mineral in sandstones, conglomerates, and red beds, commonly filling voids from the decomposition of organic material.
IMA Status:
Valid Species (Pre-IMA) 1830
Locality:
Mt. Efimiatsk and elsewhere in the Okhansk region, Middle Kama River area, Perm Basin, Ural Mountians, Russia. Link to MinDat.org Location Data.
Name Origin:
Named for Prince A. Volkonskoi, Minister of the Imperial Court, Russia.
Name Pronunciation:
Volkonskoite + Pronunciation
Synonym:
Volchonskoite
Wolchonskoite
Volkonskoite Image
Images:
Volkonskoite
Comments: Specimen of massive, green volkonskoite.
Location: Efimyatskaja Perm, Ural Mts., Russia.
Scale: 1.1 x 1 cm.
© John Veevaert
Volkonskoite Crystallography
Axial Ratios:
a:b:c =0.5771:1:1.6107
Cell Dimensions:
a = 5.16, b = 8.94, c = 14.4, Z = 2; beta = 90° V = 664.28 Den(Calc)= 2.38
Crystal System:
Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/m
Physical Properties of Volkonskoite
Cleavage:
{001} Perfect
Color:
Yellow, Olive green, Bright green.
Density:
2 - 2.5, Average = 2.25
Diaphaneity:
Subopaque
Fracture:
Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.
Habit:
Scaly - Morphology like fish scales.
Hardness:
1.5-2 - Talc-Gypsum
Luster:
Resinous
Streak:
blue green
Optical Properties of Volkonskoite
Gladstone-Dale:
CI meas = 0.005 (Superior) - where the CI = (1-KPDmeas /KC ) CI calc = 0.06 (Fair) - where the CI = (1-KPDcalc /KC )
KPDcalc = 0.2365,KPDmeas = 0.2501,KC = 0.2515 Ncalc = 1.5 - 1.63
Optical Data:
Biaxial (-), a=1.551-1.56, b=1.564, g=1.569, bire=0.0090-0.0180, 2V(Calc)=62-84, 2V(Meas)=small.
Calculated Properties of Volkonskoite
Electron Density:
Bulk Density (Electron Density)=2.26 gm/cc note: Specific Gravity of Volkonskoite =2.25 gm/cc.
Fermion Index:
Fermion Index = 0.02 Boson Index = 0.98
Photoelectric:
PEVolkonskoite = 4.99 barns/electronU=PEVolkonskoite x r Electron Density= 11.29 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Volkonskoite is Not Radioactive
Volkonskoite Classification
Dana Class:
71.03.01a.04 (71) Phyllosilicate Sheets of Six-Membered Rings
(71.03) with 2:1 clays
(71.03.01a) Smectite group (Dioctahedral Smectites)
71.03.01a.01 Beidellite Na0.5Al2(Si3.5Al0.5)O10(OH)2•n(H2O) C 2/m or ORTH 2/m
71.03.01a.02 Montmorillonite (Na,Ca)0,3(Al,Mg)2Si4O10(OH)2•n(H2O) C 2/m 2/m
71.03.01a.03 Nontronite Na0.3Fe2(Si,Al)4O10(OH)2•n(H2O) C 2/m 2/m
71.03.01a.04 Volkonskoite Ca0.3(Cr,Mg,Fe)2(Si,Al)4O10(OH)2•4(H2O) C 2/m 2/m
71.03.01a.05 Swinefordite (Li,Ca0.5,Na)0.72(Li,Al,Mg)2.66(Si,Al)4O10(OH,F)2•2(H2O) C 2/m (MON or ORTH) 2/m
Strunz Class:
09.EC.40 09 - SILICATES (Germanates)
09.E - Phyllosilicates
09.EC -Phyllosilicates with mica sheets, composed of tetrahedral and octahedral nets
09.EC.40 Almbosite ? Fe5Fe4V4Si3O27 Ortho ? Ortho
09.EC.40 Beidellite Na0.5Al2(Si3.5Al0.5)O10(OH)2•n(H2O) C 2/m or ORTH 2/m
09.EC.40 Kurumsakite (Zn,Ni,Cu)8Al8V2Si5O35•27(H2O)(?) Unk Ortho
09.EC.40 Montmorillonite (Na,Ca)0,3(Al,Mg)2Si4O10(OH)2•n(H2O) C 2/m 2/m
09.EC.40 Nontronite Na0.3Fe2(Si,Al)4O10(OH)2•n(H2O) C 2/m 2/m
09.EC.40 Volkonskoite Ca0.3(Cr,Mg,Fe)2(Si,Al)4O10(OH)2•4(H2O) C 2/m 2/m
09.EC.40 Yakhontovite (Ca,K)0.5(Cu,Fe,Mg)2Si4O10(OH)2•3(H2O) C 2/m 2/m
Other Volkonskoite Information
References:
NAME( AntBidBlaNic2) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic2)
See Also:
Links to other databases for Volkonskoite :
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 Volkonskoite using:
[AOL ]
[Bing ]
[Dog Pile ]
[GeoScienceWorld ]
[HotBot ]
[Ixquick ]
[Lycos ]
[MAMMA ]
[Scirus ]
[Teoma ]
[WebCrawler ]
[Wikipedia ]
[YAHOO ]
Visit our Advertisers for Volkonskoite :
Ask about Volkonskoite 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 Volkonskoite Specimen Label here :
Volkonskoite
Ca0.3(Cr+++,Mg,Fe+++)2(Si,Al)4O10(OH)2•4(H2O)
Dana No: 71.03.01a.04 Strunz No: 09.EC.40
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.