Johntomaite Mineral Data
General Johntomaite Information
Chemical Formula:
Ba(Fe++,Ca,Mn++)2Fe+++2(PO4)3(OH)3
Composition:
Molecular Weight = 690.07 gm
Barium 19.90 % Ba 22.22 % BaO
Calcium 2.32 % Ca 3.25 % CaO
Manganese 2.39 % Mn 3.08 % MnO
Iron 26.71 % Fe 13.53 % FeO / 23.14 % Fe2 O3
Phosphorus 13.47 % P 30.85 % P2 O5
Hydrogen 0.44 % H 3.92 % H2 O
Oxygen 34.78 % O
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
BaFe2+ 1.3 Ca0.4 Mn2+ 0.3 Fe3+ 2 (PO4 )3 (OH)3
Environment:
Occurs as an extremely rare mineral on the mine dumps. Fe 2+ -analogue of perloffite and new member of the bjarebyite group of barium phosphates.
IMA Status:
Approved IMA 1999 (Dana # Added)
Locality:
Spring Creek copper mine near Wilmington in the southern Flinders Ranges of South Australia. Link to MinDat.org Location Data.
Name Origin:
Named after Mr. John Toma, amateur mineralogist and finder of the mineral.
Synonym:
IMA1999-009
Johntomaite Crystallography
Axial Ratios:
a:b:c =0.7443:1:0.4048
Cell Dimensions:
a = 9.199, b = 12.359, c = 5.004, Z = 2; beta = 100.19° V = 559.93 Den(Calc)= 4.09
Crystal System:
Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 21 /m
X Ray Diffraction:
By Intensity(I/Io ): 3.159(1)(031,221), 2.749(0.5)(221,3 11), 2.983(0.5)(211), 3.091(0.4)(1 31), 4.573(0.4)(011), 9.1(0.3), 5.11(0.2),
Forms:
Mouse
Dbl Clk - Start-Stop Rotation
RMB - Cycle Display Modes
Drag1 - Manipulate Crystal
Drag2 - Resize
Keyboard
S - Stereo
I - Indicies
<space> - Start-Stop Rotation
F - Fit to Screen
M - Menu
Help on Above
Forms:
( 1 3 1 )
( 0 0 1)
( 1 0 0)
Warning: this java applet does not work in some browsers because of security restrictions.
Physical Properties of Johntomaite
Cleavage:
{100} Perfect
Color:
Greenish black.
Density:
4.05
Diaphaneity:
Translucent to opaque
Fracture:
Irregular - Flat surfaces (not cleavage) fractured in an irregular pattern.
Habit:
Microscopic Crystals - Crystals visible only with microscopes.
Habit:
Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).
Hardness:
4.5 - Between Fluorite and Apatite
Luster:
Vitreous - Greasy
Streak:
dark greenish gray
Optical Properties of Johntomaite
Gladstone-Dale:
CI meas = 0.024 (Excellent) - where the CI = (1-KPDmeas /KC ) CI calc = 0.034 (Excellent) - where the CI = (1-KPDcalc /KC )
KPDcalc = 0.2024,KPDmeas = 0.2044,KC = 0.2094 Ncalc = 1.85 - 1.86
Optical Data:
Biaxial (-), a=1.817, b=1.829, g=1.837, bire=0.0200, 2V(Calc)=78, 2V(Meas)=80-85. Dispersion strong.
Calculated Properties of Johntomaite
Electron Density:
Bulk Density (Electron Density)=3.82 gm/cc note: Specific Gravity of Johntomaite =4.05 gm/cc.
Fermion Index:
Fermion Index = 0.04 Boson Index = 0.96
Photoelectric:
PEJohntomaite = 94.45 barns/electronU=PEJohntomaite x r Electron Density= 360.65 barns/cc.
Radioactivity:
GRapi = 0 (Gamma Ray American Petroleum Institute Units) Johntomaite is Not Radioactive
Johntomaite Classification
Dana Class:
41.09.01.05 (41) Anhydrous Phosphates, etc. Containing Hydroxyl or Halogen
(41.09) where (A B)5 (XO4)3 Zq
(41.09.01) Kulanite Group
41.09.01.01 Kulanite Ba(Fe,Mn,Mg)2Al2(PO4)3(OH)3 P 21 /m 2/m
41.09.01.02 Penikisite BaMg2Al2(PO4)3(OH)3 P1 1
41.09.01.03 Bjarebyite (Ba,Sr)(Mn,Fe,Mg)2Al2(PO4)3(OH)3 P 21 /m 2/m
41.09.01.04 Perloffite Ba(Mn,Fe)2Fe2(PO4)3(OH)3 P 21 /m 2/m
41.09.01.05 Johntomaite ! Ba(Fe,Ca,Mn)2Fe2(PO4)3(OH)3 P 21 /m 2/m
Strunz Class:
08.BH.20 08 - PHOSPHATES, ARSENATES, VANADATES
08.B - Phosphates, etc. with Additional Anions, without H2O
08.BH -With medium-sized and large cations, (OH,etc.):RO4 = 1:1
08.BH.20 Bjarebyite (Ba,Sr)(Mn,Fe,Mg)2Al2(PO4)3(OH)3 P 21 /m 2/m
08.BH.20 Kulanite Ba(Fe,Mn,Mg)2Al2(PO4)3(OH)3 P 21 /m 2/m
08.BH.20 Penikisite BaMg2Al2(PO4)3(OH)3 P1 1
08.BH.20 Perloffite Ba(Mn,Fe)2Fe2(PO4)3(OH)3 P 21 /m 2/m
08.BH.20 Johntomaite ! Ba(Fe,Ca,Mn)2Fe2(PO4)3(OH)3 P 21 /m 2/m
Other Johntomaite Information
References:
NAME( MinPet, Vol 70, p 1-14) PHYS. PROP.(MinPet, Vol 70, p 1-14) OPTIC PROP.(MinPet, Vol 70, p 1-14)
See Also:
Links to other databases for Johntomaite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - Handbook of Mineralogy (MinSocAm)
7 - Handbook of Mineralogy (UofA)
8 - MinDAT
9 - Mineralienatlas (Deutsch)
10 - Mineralogy and Petrology
11 - Online Mineral Museum
12 - QUT Mineral Atlas
13 - Ruff.Info
Search for Johntomaite using:
[AOL ]
[Bing ]
[Dog Pile ]
[GeoScienceWorld ]
[HotBot ]
[Ixquick ]
[Lycos ]
[MAMMA ]
[Scirus ]
[Teoma ]
[WebCrawler ]
[Wikipedia ]
[YAHOO ]
Visit our Advertisers for Johntomaite :
Ask about Johntomaite 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
Espa�ol
Print or Cut-and-Paste your Johntomaite Specimen Label here :
Johntomaite
Ba(Fe++,Ca,Mn++)2Fe+++2(PO4)3(OH)3
Dana No: 41.09.01.05 Strunz No: 08.BH.20
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.