Roedderite Mineral Data

General Roedderite Information

Chemical Formula:

(Na,K)2(Mg,Fe++)5Si12O30

Composition:

Molecular Weight = 1,031.99 gm

Potassium 1.89 % K 2.28 % K₂O

Sodium 3.34 % Na 4.50 % Na₂O

Magnesium 8.83 % Mg 14.65 % MgO

Iron 6.76 % Fe 8.70 % FeO

Silicon 32.66 % Si 69.87 % SiO₂

Oxygen 46.51 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Na_1.5K_0.5Mg_3.75Fe²⁺_1.25Si₁₂O₃₀

Environment:

In vesicles in contact metamorphosed basement gneiss xenoliths in leucite tephrite (Bellerberg volcano, Germany); an accessory mineral in an enstatite chondrite (Indarch meteorite). Forms a series with eifelite.

IMA Status:

Approved IMA 1966

Locality:

In the Indarch, Witchita County, and Canyon Diablo meteorites. Link to MinDat.org Location Data.

Name Origin:

Named for Edwin Woods Roedder (1919- ), mineralogist, U.S. Geological Survey, who noted the synthetic compound.

Name Pronunciation:

Roedderite + Pronunciation

Synonym:

ICSD 68545

PDF 23-76

Roedderite Image

Images:

Roedderite

Comments: Deep green transparent roedderite microcrystal.
Location: Bellerberg, Eifel, Rheinland-Pflaz, Germany. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Roedderite Crystallography

Axial Ratios:

a:c = 1:1.40792

Cell Dimensions:

a = 10.139, c = 14.275, Z = 2; V = 1,270.86 Den(Calc)= 2.70

Crystal System:

Hexagonal - Dihexagonal Dipyramidal H-M Symbol (6/m 2/m 2/m) Space Group: P 6₃/mmc

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

By Intensity(I/I_o): 3.57(1), 3.239(0.77), 2.922(0.67),

Physical Properties of Roedderite

Cleavage:

None

Color:

Blue green, Colorless, Yellow, Reddish brown.

Density:

2.6

Diaphaneity:

Transparent

Hardness:

5-6 - Between Apatite and Orthoclase

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Roedderite

Gladstone-Dale:

CI meas= -0.017 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.021 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1998,KPDmeas= 0.2075,KC= 0.204
Ncalc = 1.53 - 1.55

Optical Data:

Uniaxial (+), w=1.537, e=1.542, bire=0.0050.

Calculated Properties of Roedderite

Electron Density:

Bulk Density (Electron Density)=2.58 gm/cc
note: Specific Gravity of Roedderite =2.60 gm/cc.

Fermion Index:

Fermion Index = 0.02
Boson Index = 0.98

Photoelectric:

PE_Roedderite= 3.68 barns/electron
U=PE_Roedderite x r_electron= 9.48 barns/cc.

Radioactivity:

GRapi = 27.10 (Gamma Ray American Petroleum Institute Units)
Concentration of Roedderite per GRapi unit = 3.69 (%)

Estimated Radioactivity from Roedderite - barely detectable

Roedderite Classification

Dana Class:

63.02.01a.14 (63)Cyclosilicate Condensed Rings

(63.02)6-membered rings

(63.02.01a)Milarite - Osumilite group (Milarite - Osumilite subgroup)

63.02.01a.01 Brannockite KSn2Li3Si12O30 P 6/mcc 6/m 2/m 2/m

63.02.01a.02 Chayesite K(Mg,Fe)4Fe(Si12O30) P 6/mcc 6/m 2/m 2/m

63.02.01a.03 Darapiosite KNa2Zr[Li(Mn,Zr)2Si12O30] P 6/mcc 6/m 2/m 2/m

63.02.01a.04 Eifelite KNa3Mg4Si12O30 P 6/mcc 6/m 2/m 2/m

63.02.01a.05 Merrihueite (K,Na)2(Fe,Mg)5Si12O30 P 6/mcc 6/m 2/m 2/m

63.02.01a.06 Osumilite-(Fe) (K,Na)(Fe,Mg)2(Al,Fe)3(Si,Al)12O30 P 6/mcc 6/m 2/m 2/m

63.02.01a.07 Osumilite-(Mg) (K,Na)(Mg,Fe)2(Al,Fe)3(Si,Al)12O30 P 6/mcc 6/m 2/m 2/m

63.02.01a.08 Poudretteite KNa2B3Si12O30 P 6/mcc 6/m 2/m 2/m

63.02.01a.09 Sugilite KNa2(Fe,Mn,Al)2Li3Si12O30 P 6/mcc 6/m 2/m 2/m

63.02.01a.10 Yagiite (Na,K)3Mg4(Al,Mg)6(Si,Al)24O60 P 6/mmc 6/m 2/m 2/m

63.02.01a.11 Dusmatovite K(K,Na,[])(Mn,Y,Zr)2(Zn,Li)3Si12O30 P 6/mcc 6/m 2/m 2/m

63.02.01a.12 Milarite K2Ca4Al2Be4Si24O60•(H2O) P 6/mcc 6/m 2/m 2/m

63.02.01a.13 Sogdianite (K,Na)2(Li,Fe,Al)3ZrSi12O30 P 6/mmm 6/m 2/m 2/m

63.02.01a.14 Roedderite (Na,K)2(Mg,Fe)5Si12O30 P 6₃/mmc 6/m 2/m 2/m

63.02.01a.15 Berezanskite! KLi3Ti2Si12O30 P 6/mcc 6/m 2/m 2/m

63.02.01a.16 Shibkovite! K(Ca,Mn,Na)2(K2-x,[]x)2ZnSi12O30(x~0.8) P 6/mcc 6/m 2/m 2/m

63.02.01a.17 Trattnerite! (Fe,Mg)2(Mg,Fe)3(Si12O30) P 6/mcc 6/m 2/m 2/m

63.02.01a.18 Almarudite! K([],Na)2(Mn,Fe,Mg)2(Be,Al)3[Si12O30] P 6/mcc 6/m 2/m 2/m

63.02.01a.19 Oftedalite! (Sc,Ca)2KBe3Si12O30 P 6/mmc 6/m 2/m 2/m

63.02.01a.20 Klochite ([]1Na1)KFe2Zn3[Si12O30] P 6/mcc 6/m 2/m 2/m

63.02.01a.21 Friedrichbeckeite! K([],Na)Mg2(Be2Mg)Si12O30 P 6/mcc 6/m 2/m 2/m

Strunz Class:

09.CM.05 09 - SILICATES (Germanates)

09.C - Cyclosilicates

09.CM -[Si6O18]12- 6-membered double rings (sechser-Doppelringe)

09.CM.05 Brannockite KSn2Li3Si12O30 P 6/mcc 6/m 2/m 2/m

09.CM.05 Armenite BaCa2Al6Si9O30•2(H2O) Pnc2 mm2

09.CM.05 Berezanskite! KLi3Ti2Si12O30 P 6/mcc 6/m 2/m 2/m

09.CM.05 Dusmatovite K(K,Na,[])(Mn,Y,Zr)2(Zn,Li)3Si12O30 P 6/mcc 6/m 2/m 2/m

09.CM.05 Chayesite K(Mg,Fe)4Fe(Si12O30) P 6/mcc 6/m 2/m 2/m

09.CM.05 Shibkovite! K(Ca,Mn,Na)2(K2-x,[]x)2ZnSi12O30(x~0.8) P 6/mcc 6/m 2/m 2/m

09.CM.05 Eifelite KNa3Mg4Si12O30 P 6/mcc 6/m 2/m 2/m

09.CM.05 Darapiosite KNa2Zr[Li(Mn,Zr)2Si12O30] P 6/mcc 6/m 2/m 2/m

09.CM.05 Merrihueite (K,Na)2(Fe,Mg)5Si12O30 P 6/mcc 6/m 2/m 2/m

09.CM.05 Roedderite (Na,K)2(Mg,Fe)5Si12O30 P 6₃/mmc 6/m 2/m 2/m

09.CM.05 Milarite K2Ca4Al2Be4Si24O60•(H2O) P 6/mcc 6/m 2/m 2/m

09.CM.05 Osumilite-(Fe) (K,Na)(Fe,Mg)2(Al,Fe)3(Si,Al)12O30 P 6/mcc 6/m 2/m 2/m

09.CM.05 Osumilite-(Mg) (K,Na)(Mg,Fe)2(Al,Fe)3(Si,Al)12O30 P 6/mcc 6/m 2/m 2/m

09.CM.05 Poudretteite KNa2B3Si12O30 P 6/mcc 6/m 2/m 2/m

09.CM.05 Sugilite KNa2(Fe,Mn,Al)2Li3Si12O30 P 6/mcc 6/m 2/m 2/m

09.CM.05 Sogdianite (K,Na)2(Li,Fe,Al)3ZrSi12O30 P 6/mmm 6/m 2/m 2/m

09.CM.05 Oftedalite! (Sc,Ca)2KBe3Si12O30 P 6/mmc 6/m 2/m 2/m

09.CM.05 Yagiite (Na,K)3Mg4(Al,Mg)6(Si,Al)24O60 P 6/mmc 6/m 2/m 2/m

09.CM.05 Trattnerite! (Fe,Mg)2(Mg,Fe)3(Si12O30) P 6/mcc 6/m 2/m 2/m

09.CM.05 Almarudite! K([],Na)2(Mn,Fe,Mg)2(Be,Al)3[Si12O30] P 6/mcc 6/m 2/m 2/m

Other Roedderite Information

References:

NAME( AntBidBlaNic2) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Roedderite :
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 Roedderite using:

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

Visit our Advertisers for Roedderite :

Ask about Roedderite 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 Roedderite Specimen Label here :

Roedderite

(Na,K)2(Mg,Fe++)5Si12O30
Dana No: 63.02.01a.14 Strunz No: 09.CM.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.