Osumilite-(Mg) Mineral Data

General Osumilite-(Mg) Information

Chemical Formula:

(K,Na)(Mg,Fe++)2(Al,Fe+++)3(Si,Al)12O30

Composition:

Molecular Weight = 1,015.74 gm

Potassium 2.89 % K 3.48 % K₂O

Sodium 0.57 % Na 0.76 % Na₂O

Magnesium 3.59 % Mg 5.95 % MgO

Aluminum 13.95 % Al 26.35 % Al₂O₃

Iron 6.87 % Fe 3.54 % FeO / 5.90 % Fe₂O₃

Silicon 24.89 % Si 53.24 % SiO₂

Oxygen 47.25 % O

______ ______

100.00 % 99.21 % = TOTAL OXIDE

Empirical Formula:

K_0.75Na_0.25Mg_1.5Fe²⁺_0.5Al_2.25Fe³⁺_0.75Si₉Al₃O₃₀

IMA Status:

Approved IMA 1983

Locality:

Historic province of Osumi in Sakkabira, Kyushu, Japan. Link to MinDat.org Location Data.

Name Origin:

Named for the locality and the composition.

Name Pronunciation:

Osumilite-(Mg) + Pronunciation

Synonym:

ICSD 202731

PDF 30-942

Osumilite-(Mg) Image

Images:

Osumilite-(Mg)

Comments: Sapphire-blue colored osumilite-(Mg) crystal in dacite.
Location: Yamanoguchi, Iriki, Satsuma-gun, Kagoshima Prefecture, Kyushu Island, Japan. Scale: Crystal Size 0.05 cm.
© Jeff Weissman / Photographic Guide to Mineral Species

Osumilite-(Mg) Crystallography

Axial Ratios:

a:c = 1:1.40901

Cell Dimensions:

a = 10.117, c = 14.255, Z = 2; V = 1,263.58 Den(Calc)= 2.67

Crystal System:

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

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

By Intensity(I/I_o): 3.22(1), 4.11(0.6), 5.01(0.6),

Physical Properties of Osumilite-(Mg)

Cleavage:

None

Color:

Brown, Green, Dark blue, Black.

Density:

2.62 - 2.64, Average = 2.63

Diaphaneity:

Translucent to Opaque

Fracture:

Brittle - Generally displayed by glasses and most non-metallic minerals.

Hardness:

5-6 - Between Apatite and Orthoclase

Luster:

Vitreous (Glassy)

Optical Properties of Osumilite-(Mg)

Gladstone-Dale:

CI meas= 0.022 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= 0.037 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2029,KPDmeas= 0.206,KC= 0.2107
Ncalc = 1.55 - 1.56

Optical Data:

Uniaxial (+), w=1.5406, e=1.543, bire=0.0024.

Calculated Properties of Osumilite-(Mg)

Electron Density:

Bulk Density (Electron Density)=2.60 gm/cc
note: Specific Gravity of Osumilite-(Mg) =2.63 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_{Osumilite-(Mg)}= 3.77 barns/electron
U=PE_{Osumilite-(Mg)} x r_electron= 9.80 barns/cc.

Radioactivity:

GRapi = 41.16 (Gamma Ray American Petroleum Institute Units)
Concentration of Osumilite-(Mg) per GRapi unit = 2.43 (%)

Estimated Radioactivity from Osumilite-(Mg) - barely detectable

Osumilite-(Mg) Classification

Dana Class:

63.02.01a.07 (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 Osumilite-(Mg) Information

References:

NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Osumilite-(Mg) :
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

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Osumilite-(Mg)

(K,Na)(Mg,Fe++)2(Al,Fe+++)3(Si,Al)12O30
Dana No: 63.02.01a.07 Strunz No: 09.CM.05
Locality:

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