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 - Prismatic H-M Symbol (2/m) Space Group: P 2₁/m

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 :

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:

Dakota Matrix
Excalibur Minerals
Exceptional Minerals
Hudson Insitute
John Betts Fine Minerals
Mc Dougall Minerals
Mineral News
Rock and Mineral Shows
Weinrich Minerals, Inc.