Gamagarite Mineral Data

General Gamagarite Information

Chemical Formula:

Ba2(Fe+++,Mn+++)(VO4)2(OH)

Composition:

Molecular Weight = 577.16 gm

Barium 47.59 % Ba 53.13 % BaO

Manganese 2.38 % Mn 3.42 % Mn₂O₃

Vanadium 17.65 % V 31.51 % V₂O₅

Iron 7.26 % Fe 10.38 % Fe₂O₃

Hydrogen 0.17 % H 1.56 % H₂O

Oxygen 24.95 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Ba₂Fe³⁺_0.75Mn³⁺_0.25(VO₄)₂(OH)

Environment:

Banded manganese ore replacing shale.

IMA Status:

Valid Species (Pre-IMA) 1943

Locality:

Along Gamagara Ridge, on Gloucester Farm, about 27 km north of Postmasburg, Cape Province, South Africa. Link to MinDat.org Location Data.

Name Origin:

Named for the locality.

Name Pronunciation:

Gamagarite + Pronunciation

Synonym:

ICSD 68348

PDF 41-1413

Gamagarite Image

Images:

Gamagarite

Comments: Dark red-brown crystalline gamagarite in white calcite.
Location: Molinello Mine, Val Graveglia, Genova, Liguria, Italy. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Gamagarite Crystallography

Axial Ratios:

a:b:c =1.4829:1:1.2771

Cell Dimensions:

a = 9.15, b = 6.17, c = 7.88, Z = 2; beta = 112.7° V = 410.41 Den(Calc)= 4.67

Crystal System:

Monoclinic - PrismaticH-M Symbol (2/m) Space Group: P 2₁/m

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

Basso R , Palenzona A , Zefiro L , Neues Jahrbuch fur Mineralogie, Monatshefte , 1987 (1987) p.295-304, Gamagarite: new occurrence and crystal structure refinement, Locality: a manganese ore deposit at Molinello mine, Val Graveglia, Eastern Liguria, Italy

Physical Properties of Gamagarite

Cleavage:

{001} Distinct, {100} Distinct, {101} Indistinct

Color:

Brownish black, Dark brown, Black.

Density:

4.62

Diaphaneity:

Translucent to Opaque

Fracture:

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

Hardness:

4.5-5 - Near Apatite

Luster:

Adamantine

Optical Properties of Gamagarite

Gladstone-Dale:

CI meas= -0.029 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.018 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2274,KPDmeas= 0.2299,KC= 0.2234
Ncalc = 2.03 - 2.04

Optical Data:

Biaxial (+), a=2.016, b=2.04, g=2.13, bire=0.1140, 2V(Calc)=58, 2V(Meas)=46-62.

Calculated Properties of Gamagarite

Electron Density:

Bulk Density (Electron Density)=4.15 gm/cc
note: Specific Gravity of Gamagarite =4.67 gm/cc.

Fermion Index:

Fermion Index = 0.08
Boson Index = 0.92

Photoelectric:

PE_Gamagarite= 221.06 barns/electron
U=PE_Gamagarite x rElectron Density= 918.50 barns/cc.

Radioactivity:

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

Gamagarite Classification

Dana Class:

41.10.04.03 (41)Anhydrous Phosphates, etc. Containing Hydroxyl or Halogen

(41.10)where (A++ B++)3 (XO4)2 Zq

(41.10.04)Goedkenite Group

41.10.04.01 Goedkenite (Sr,Ca)2Al(PO4)2(OH) P 2₁/m 2/m

41.10.04.02 Bearthite Ca2Al(PO4)2(OH) P 2₁/m 2/m

41.10.04.03 Gamagarite Ba2(Fe,Mn)(VO4)2(OH) P 2₁/m 2/m

41.10.04.04 Tokyoite! Ba2Mn(VO4)2(OH) P 2₁/m 2/m

Strunz Class:

08.BG.05 08 - PHOSPHATES, ARSENATES, VANADATES

08.B - Phosphates, etc. with Additional Anions, without H2O

08.BG -With medium-sized and large cations, (OH, etc.):RO4 = 0.5:1

08.BG.05 Arsenbrackebuschite Pb2(Fe,Zn)(AsO4)2•(H2O) P 2₁/m 2/m

08.BG.05 Bearthite Ca2Al(PO4)2(OH) P 2₁/m 2/m

08.BG.05 Arsentsumebite Pb2Cu(AsO4)(SO4)(OH) P 2₁/m 2/m

08.BG.05 Brackebuschite Pb2(Mn,Fe)(VO4)2(OH) P 2₁/m 2/m

08.BG.05 Feinglosite! Pb2(Zn,Fe)[(As,S)O4]2•(H2O) P 2₁,P 2₁/m Mono

08.BG.05 Gamagarite Ba2(Fe,Mn)(VO4)2(OH) P 2₁/m 2/m

08.BG.05 Goedkenite (Sr,Ca)2Al(PO4)2(OH) P 2₁/m 2/m

08.BG.05 Tsumebite Pb2Cu(PO4)(SO4)(OH) P 2₁/m 2/m

08.BG.05 Calderonite! Pb2Fe(VO4)2(OH) P 2₁/m 2/m

08.BG.05 Bushmakinite! Pb2Al(PO4)(VO4)(OH) P 2₁/m 2/m

08.BG.05 Tokyoite! Ba2Mn(VO4)2(OH) P 2₁/m 2/m

Other Gamagarite Information

References:

NAME( AntBidBlaNic4) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Gamagarite :
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
15 - WWW-MINCRYST

Search for Gamagarite using:

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

Visit our Advertisers for Gamagarite :

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

Ask about Gamagarite 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 Gamagarite Specimen Label here :

Gamagarite

Ba2(Fe+++,Mn+++)(VO4)2(OH)
Dana No: 41.10.04.03 Strunz No: 08.BG.05
Locality:

Notes: