Rhonite Mineral Data

General Rhonite Information

Chemical Formula:

Ca2(Mg,Fe++,Fe+++,Ti)6(Si,Al)6O20

Composition:

Molecular Weight = 814.43 gm

Potassium 0.48 % K 0.58 % K₂O

Sodium 0.56 % Na 0.76 % Na₂O

Calcium 8.86 % Ca 12.39 % CaO

Magnesium 7.46 % Mg 12.37 % MgO

Titanium 5.88 % Ti 9.81 % TiO₂

Aluminum 8.94 % Al 16.90 % Al₂O₃

Iron 17.14 % Fe 11.47 % FeO / 11.76 % Fe₂O₃

Silicon 11.38 % Si 24.35 % SiO₂

Oxygen 39.29 % O

______ ______

100.00 % 100.39 % = TOTAL OXIDE

Empirical Formula:

Ca_1.8Na_0.2K_0.1Mg_2.5Fe²⁺_1.3Fe³⁺_1.2TiSi_3.3Al_2.7O₂₀

Environment:

In silica-undersaturated, alkalic, mafic to intermediate igneous rocks, as a primary mineral or alteration of amphiboles.

IMA Status:

Valid Species (Pre-IMA) 1907

Locality:

Rhon Mountains, at Scharnhausen, near Stuttgart, Germany. Link to MinDat.org Location Data.

Name Origin:

Named for the locality.

Name Pronunciation:

Rhonite

Synonym:

Rhoenite

Rhonite Image

Images:

Rhonite

Comments: Brown, striated, tabular crystal of rhonite on matrix.
Location: Sattleberg, Laacher See, Rhineland-Pal., Germany. Scale: Not Given.
© Lou Perloff / Photo Atlas of Minerals

Rhonite Crystallography

Axial Ratios:

a:b:c =0.9592:1:0.8395

Cell Dimensions:

a = 10.478, b = 10.923, c = 9.17, Z = 2; alpha = 101.43°, beta = 96.95°, gamma = 129.68° V = 785.90 Den(Calc)= 3.44

Crystal System:

Triclinic - Pinacoidal H-M Symbol ( 1) Space Group: P1

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 2.947(1), 2.55(0.7), 2.691(0.65),

Physical Properties of Rhonite

Cleavage:

{010} Good, {001} Good

Color:

Brown.

Density:

3.4 - 3.76, Average = 3.58

Diaphaneity:

Subtranslucent to Opaque

Habit:

Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).

Habit:

Skeletal - Crystals form crude outlines with missing faces.

Habit:

Tabular - Form dimensions are thin in one direction.

Hardness:

5-6 - Between Apatite and Orthoclase

Luster:

Sub Metallic

Optical Properties of Rhonite

Gladstone-Dale:

CI meas= 0.032 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= 0.042 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2261,KPDmeas= 0.2286,KC= 0.2361
Ncalc = 1.8 - 1.89

Optical Data:

Biaxial (+), a=1.795-1.81, b=1.806-1.825, g=1.83-1.845, bire=0.0350, 2V(Calc)=70-84, 2V(Meas)=50-90. Dispersion r > v extreme.

Pleochroism (x):

dark greenish brown or red brown.

Pleochroism (y):

dark reddish brown or dark greenish brown.

Pleochroism (z):

dark reddish brown or black.

Calculated Properties of Rhonite

Electron Density:

Bulk Density (Electron Density)=3.50 gm/cc
note: Specific Gravity of Rhonite =3.58 gm/cc.

Fermion Index:

Fermion Index = 0.02
Boson Index = 0.98

Photoelectric:

PE_Rhonite= 8.09 barns/electron
U=PE_Rhonite x r_electron= 28.32 barns/cc.

Radioactivity:

GRapi = 6.76 (Gamma Ray American Petroleum Institute Units)
Concentration of Rhonite per GRapi unit = 14.80 (%)

Estimated Radioactivity from Rhonite - barely detectable

Rhonite Classification

Dana Class:

69.02.01a.05 (69)Inosilicate Chains with Side Branches or Loops

(69.02)with P>2

(69.02.01a)Aenigmatite and related species (Aenigmatite subgroup)

69.02.01a.01 Aenigmatite (Na,Ca)4(Fe,Ti,Mg)12Si12O40 P1 1

69.02.01a.02 Dorrite Ca2Mg2Fe4(Al,Fe)4Si2O20 P1,P 1 Tri

69.02.01a.03 Hogtuvaite (Ca,Na)2(Fe,Fe,Ti,Mg,Mn)6(Si,Be,Al)6O20 P1 1

69.02.01a.04 Krinovite NaMg2CrSi3O10 P1 1

69.02.01a.05 Rhonite Ca2(Mg,Fe,Fe,Ti)6(Si,Al)6O20 P1 1

69.02.01a.06 Serendibite Ca2(Mg,Al)6(Si,Al,B)6O20 P1 1

69.02.01a.07 Welshite Ca4Mg9Sb3O4[Si6Be3AlFe2O36] P1 1

69.02.01a.08 Wilkinsonite Na2Fe4Fe2Si6O20 P1 1

69.02.01a.09 Makarochkinite! Ca2Fe4FeTiSi4BeAlO20 P1 1

Strunz Class:

09.DH.45 09 - SILICATES (Germanates)

09.D - Inosilicates* Structural terminology according to Liebau (1985)

09.DH -Inosilicates with 4-periodic single chains, Si4O12

09.DH.45 Aenigmatite (Na,Ca)4(Fe,Ti,Mg)12Si12O40 P1 1

09.DH.45 Dorrite Ca2Mg2Fe4(Al,Fe)4Si2O20 P1,P 1 Tri

09.DH.45 Krinovite NaMg2CrSi3O10 P1 1

09.DH.45 Rhonite Ca2(Mg,Fe,Fe,Ti)6(Si,Al)6O20 P1 1

09.DH.45 Sapphirine (Mg,Al)8(Al,Si)6O20 P1 1

09.DH.45 Serendibite Ca2(Mg,Al)6(Si,Al,B)6O20 P1 1

09.DH.45 Khmaralite! (Mg,Al,Fe)16(Al,Si,Be)12O40 P 2₁/c 2/m

09.DH.45 Makarochkinite! Ca2Fe4FeTiSi4BeAlO20 P1 1

09.DH.45 Welshite Ca4Mg9Sb3O4[Si6Be3AlFe2O36] P1 1

09.DH.45 Wilkinsonite Na2Fe4Fe2Si6O20 P1 1

Other Rhonite Information

References:

NAME( AntBidBlaNic2) PHYS. PROP.(AntBidBlaNic2) OPTIC PROP.(AntBidBlaNic2)

See Also:

Links to other databases for Rhonite :
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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Rhonite

Ca2(Mg,Fe++,Fe+++,Ti)6(Si,Al)6O20
Dana No: 69.02.01a.05 Strunz No: 09.DH.45
Locality:

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