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Rhodesite Mineral Data

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General Rhodesite Information

Help on Chemical  Formula: Chemical Formula: KHCa2Si8O19•5(H2O)
Help on Composition: Composition: Molecular Weight = 732.57 gm
   Potassium   3.20 %  K     3.86 % K2O
   Sodium      1.26 %  Na    1.69 % Na2O
   Calcium    10.94 %  Ca   15.31 % CaO
   Silicon    30.67 %  Si   65.62 % SiO2
   Hydrogen    1.51 %  H    13.53 % H2O
   Oxygen     52.42 %  O
             ______        ______ 
             100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: K0.6Na0.4HCa2Si8O19•5(H2O)
Help on Environment: Environment: In a kimberlite pipe and also in altered silicic lavas.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1957
Help on Locality: Locality: Bultfontein diamond mine, Kimberley, Cape Province, South Africa. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Cecil John Rhodes (1853-1902), British founder of the DeBeers Mining Company and for Rhodes University, Grahamstown, South Africa where the mineral was studied.
Help on Name Pronunciation: Name Pronunciation: Rhodesite + Pronunciation Say RHODESITE
Help on Synonym: Synonym: ICSD 36551
  PDF 22-1253

Rhodesite Image

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  Magadiite   Rhodesite

Comments: Earth pale tan massive magadiite with dark yellow crystalline rhodesite.
Location: East Fork, Trinity River, Trinity County, California, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

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Comments: Pearly white to tan rhodesite crusts.
Location: Quarter-mile east of Trinity River, Trinity County, California, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Rhodesite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =3.5722:1:1.0755
Help on Cell Dimensions: Cell Dimensions: a = 23.416, b = 6.555, c = 7.05, Z = 2; V = 1,082.12 Den(Calc)= 2.25
Help on Crystal System: Crystal System: Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: Pmam
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 6.55(1), 4.39(0.45), 5.9(0.35),

Physical Properties of Rhodesite

Help on Cleavage: Cleavage: {100} Good
Help on Color: Color: Silky white.
Help on Density: Density: 2.36
Help on Diaphaneity: Diaphaneity: Translucent to transparent
Help on Habit: Habit: Fibrous - Crystals made up of fibers.
Help on Hardness: Hardness: 3-4 - Calcite-Fluorite
Help on Luster: Luster: Silky
Help on Streak: Streak: white

Optical Properties of Rhodesite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.044 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= -0.002 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2259,KPDmeas= 0.2154,KC= 0.2254
Ncalc = 1.51 - 1.53
Help on Optical Data: Optical Data: Biaxial (+), a=1.501-1.504, b=1.506-1.508, g=1.513-1.518, bire=0.0120-0.0140

Calculated Properties of Rhodesite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.28 gm/cc
note: Specific Gravity of Rhodesite =2.25 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.01
Boson Index = 0.99
Help on Photoelectric: Photoelectric: PERhodesite = 2.87 barns/electron
U=PERhodesite x relectron= 6.53 barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 46.76 (Gamma Ray American Petroleum Institute Units)
Concentration of Rhodesite per GRapi unit = 2.14 (%)

Estimated Radioactivity from Rhodesite - barely detectable


Rhodesite Classification

Help on  Dana Class: Dana Class: (72)Phyllosilicate Two-Dimensional Infinite Sheets with Other Than Six-Membered Rings
  (72.05)with corrugated and complex layers
  (72.05.01)Rhodesite group Rhodesite KHCa2Si8O19•5(H2O) Pmam 2/m 2/m 2/m Monteregianite-(Y) (Na,K)6(Y,Ca)2Si16O38•10(H2O) P 21/m 2/m Macdonaldite BaCa4[Si16O36(OH)2]•10(H2O) C mcm 2/m 2/m 2/m Delhayelite (Na,K)10Ca5Al6Si32O80(Cl2,F2,SO4)3•18(H2O) Pnmm 2/m 2/m 2/m Hydrodelhayelite KCa2AlSi7O17(OH)2•6(H2O) Pnm21 mm2 Seidite-(Ce)! Na4(Ce,Sr)2{Ti(OH)2(Si8O18)}(O,OH,F)4•5(H2O) C/2c 2/m
Help on  Strunz Class: Strunz Class: 09.EB.05 09 - SILICATES (Germanates)
  09.E - Phyllosilicates
  09.EB -Double nets with 4- and 6-membered rings
09.EB.05 Macdonaldite BaCa4[Si16O36(OH)2]•10(H2O) C mcm 2/m 2/m 2/m
09.EB.05 Rhodesite KHCa2Si8O19•5(H2O) Pmam 2/m 2/m 2/m

Other Rhodesite Information

Help on References: References: NAME( AntBidBlaNic2) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic2)
Help on See Also: See Also: Links to other databases for Rhodesite :
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

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Dana No: Strunz No: 09.EB.05





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