Arnhemite  Mineral Data

Arnhemite Mineral Data

Search Webmineral :
   
Home Crystal jmol jPOWD Chem X Ray Dana Strunz Properties A to Z Images Share
      News Help About

Advertisment
WE BUY COLLECTIONS & SINGLE IMPORTANT SPECIMENS

General Arnhemite Information

Help on Chemical  Formula: Chemical Formula: (K,Na)2Mg2(P2O7)•5(H2O)
Help on Composition: Composition: Molecular Weight = 620.94 gm
   Potassium   17.50 %  K    21.09 % K2O
   Sodium       3.37 %  Na    4.54 % Na2O
   Calcium      0.97 %  Ca    1.35 % CaO
   Magnesium    6.89 %  Mg   11.42 % MgO
   Manganese    0.18 %  Mn    0.23 % MnO
   Zinc         0.11 %  Zn    0.13 % ZnO
   Iron         0.27 %  Fe    0.35 % FeO
   Phosphorus  20.10 %  P    46.06 % P2O5
   Hydrogen     1.66 %  H    14.83 % H2O
   Oxygen      48.96 %  O
              ______        ______ 
              100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: K2.78Na0.91Mg1.76Ca0.15Fe2+0.03Mn2+0.02Zn0.01P4.03O13.89·5.11(H2O)
Help on Environment: Environment: Occurs as flakes that form aggregates making up the principal component of a thin layer of white, friable slag in the profile of cave-floor soil.
Help on IMA Status: IMA Status: Not Approved IMA
Help on Locality: Locality: Arnhem Cave, Namibia. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named after it's locality.
 

Search for Arnhemite Images

Click Here To Search Images:

Image not yet available on Webmineral.com

Try searching images.google.com or Mindat Picture Gallary for mineral pictures. Caution: The images retrieved may not be appropriate.

  

Arnhemite Crystallography

Help on Axial Ratios: Axial Ratios: a:c = 1:1.51446
Help on Cell Dimensions: Cell Dimensions: a = 11.06, c = 16.75, Z = 4; V = 1,774.42 Den(Calc)= 2.32
Help on Crystal System: Crystal System: HexagonalSpace Group: Unk
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 16.7(1)(001 ), 2.761(0.25)(220 ), 8.33(0.15)(011 ),2.3(0.1)(224,042), 2.216(0.05)(126 ), 4.616(0.05)(112 ), 3.184(0.05)(030 ),
 

Physical Properties of Arnhemite

Help on Cleavage: Cleavage: {001} Perfect
Help on Color: Color: White.
Help on Density: Density: 2.33 - 2.35, Average = 2.34
Help on Diaphaneity: Diaphaneity: Transparent
Help on Fracture: Fracture: Friable - The crumbly disintegration of earthy materials or highly fractured minerals.
Help on Luster: Luster: Pearly
Help on Streak: Streak: white
 

Optical Properties of Arnhemite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.029 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.038 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2196,KPDmeas= 0.2177,KC= 0.2117
Ncalc = 1.49 - 1.5
Help on Optical Data: Optical Data: Uniaxial (-), e=1.503, w=1.516, bire=0.0130.
 

Calculated Properties of Arnhemite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.35 gm/cc
note: Specific Gravity of Arnhemite =2.34 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0072609178
Boson Index = 0.9927390822
Help on Photoelectric: Photoelectric: PEArnhemite = 3.22 barns/electron
U=PEArnhemite x relectron= 7.54 barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 253.16 (Gamma Ray American Petroleum Institute Units)
Concentration of Arnhemite per GRapi unit = 0.40 (%)

Estimated Radioactivity from Arnhemite - barely detectable

 

Arnhemite Classification

Help on  Dana Class: Dana Class: 37.00.00.00 (37)Phosphate Minerals
  (37.00)Without Dana Classification Numbers
  (37.00.00)Phosphate, Thermocaca Series
 
37.00.00.00 Arnhemite* (K,Na)2Mg2(P2O7)•5(H2O) Unk Hex
 
37.00.00.00 Arsenowaylandite* BiAl3(AsO4)2(OH)6 R 3m 3 2/m
 
37.00.00.00 Auroantimonate* AuSbO3 Ortho ? Ortho
 
37.00.00.00 Barium-zinc-alumopharmacosiderite* (Ba,K)0.5(Zn,Cu)0.5(Al,Fe)4(AsO4)3•5(H2O) I 42m 4 2m
 
37.00.00.00 Chernovite-(Ce)* (Ce,Y)(AsO4) I 41/amd 4/m 2/m 2/m
 
37.00.00.00 Churchite-(Dy)* (Dy,Sm,Gd,Nd)(PO4)•2(H2O) Mono
 
37.00.00.00 Gengenbachite KFe3(H2PO4)2(HPO4)4•6H2OorKFe3H8(PO4)6•6H2O P 63mc 6mm
 
37.00.00.00 IMA2008-063 Pb[Zn0.25,[]0.75]Fe3H(AsO4)2(OH)6 C 2/c 2/m
 
37.00.00.00 IMA2009-005 (Y,Ca,REE)5[(Si,P)O4]3F P 63/m 6/m 2/m 2/m
 
37.00.00.00 IMA2009-016 Cu4H(AsO4)2(OH)3•H2O P1 1
 
37.00.00.00 Kerstenite? PbSeO4(?) P nma 2/m 2/m 2/m
 
37.00.00.00 Krasnoselskite* CoWO4 P 2/c 2/m
 
37.00.00.00 Laubmannite? Fe3Fe6(PO4)4(OH)12 Unk Ortho
 
37.00.00.00 Oxiberaunite* (Fe,Mn)Fe5(PO4)4O(OH)4•6(H2O) Mono
 
37.00.00.00 Parwanite (Na,K)(Mg,Ca)4Al8(PO4)8(CO3)(OH)7•30H2O P 2, Pm, P 2/m, P 21, Mono
 
37.00.00.00 Pyrocoproite* (Mg(K,Na))2P2O7 Unk Mono
 
37.00.00.00 Pyrophosphite* K2CaP2O7 P 21/n 2/m
 
37.00.00.00 Zinclavendulan? NaCa(Zn,Cu)5(AsO4)4Cl•4-5(H2O) Unk Ortho
Help on  Strunz Class: Strunz Class: 08.FC.20 08 - PHOSPHATES, ARSENATES, VANADATES
  08.F - Polyphosphates, Polyarsenates, [4]-Polyvanadates
  08.FC -Polyphosphates, etc., with H2O only
 
08.FC.20 Arnhemite* (K,Na)2Mg2(P2O7)•5(H2O) Unk Hex
 

Other Arnhemite Information

Help on References: References: NAME( AmMin, v84:193) PHYS. PROP.(Am.Min.,Vol.84,p193,1999) OPTIC PROP.(AmMin, v84:193)
Help on See Also: See Also: Links to other databases for Arnhemite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - MinDAT
7 - Mineralienatlas (Deutsch)
8 - Online Mineral Museum
9 - QUT Mineral Atlas
10 - Ruff.Info

Search for Arnhemite using:

Google
 
Web webmineral.com
[AOL] [Bing] [Dog Pile] [GeoScienceWorld] [HotBot] [Ixquick] [Lycos] [MAMMA] [Scirus] [Teoma] [WebCrawler] [Wikipedia] [YAHOO]

Visit our Advertisers for Arnhemite :

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

Ask about Arnhemite 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 Espaņol

Print or Cut-and-Paste your Arnhemite Specimen Label here :

Arnhemite

(K,Na)2Mg2(P2O7)•5(H2O)
Dana No: 37.00.00.00 Strunz No: 08.FC.20
Locality:

 

Notes: