Semenovite Mineral Data +

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General Semenovite Information
Chemical Formula:	(Na,Ca)9(Ce,La)2(Fe++,Mn)(Si,Be)20(O,OH,F)48
Composition:	Molecular Weight = 1,853.28 gm
	Potassium         0.21 %  K     0.25 % K2O
	Sodium            8.31 %  Na   11.20 % Na2O
	Calcium           4.33 %  Ca    6.05 % CaO
	Lanthanum         6.00 %  La    7.03 % La2O3
	Cerium            5.29 %  Ce    6.20 % Ce2O3
	La,Ce,Pr,Nd,Sm,   3.11 %  RE    3.63 % REE2O3
	Yttrium           1.44 %  Y     1.83 % Y2O3
	Manganese         1.48 %  Mn    1.91 % MnO
	Beryllium         3.01 %  Be    8.37 % BeO
	Aluminum          0.44 %  Al    0.83 % Al2O3
	Zinc              0.35 %  Zn    0.44 % ZnO
	Iron              2.41 %   Fe    0.78 % FeO /  2.59 % Fe2O3
	Silicon          20.46 %  Si   43.77 % SiO2
	Hydrogen          0.22 %  H     1.94 % H2O
	Oxygen           38.33 %  O
	Fluorine          4.61 %  F     4.61 % F
	-   %   F    -1.94 % -O=F2
	______        ______
	100.00 %       99.48 % = TOTAL OXIDE
Empirical Formula:	Na6.7Ca2K0.1La0.8Ce0.7Y0.3REE0.4Mn2+0.5Fe2+0.2Zn0.1Fe3+0.6Si13.5Be6.2 Al0.3O40.4F4.5(OH)4
Environment:	Occurs in border zone of the only epididymite-eudidymite bearing albitite, in cavities and fractures.
IMA Status:	Approved IMA 1972
Locality:	Ilimaussaq complex, South Greenland. Link to MinDat.org Location Data.
Name Origin:	Named for Yevgeny Ivanovich Semenov, (1951-), Russian mineralogist, IMGRE, Moscow, Russia.
Semenovite Image
Images:	Semenovite Comments: Tan crystals of semenovite to 1 mm across on matrix. Location: Ilimaussaq, Tasseq, Greenland. Scale: Picture size 1 cm. © John Veevaert
Semenovite Crystallography
Axial Ratios:	a:b:c =1.0031:1:0.7186
Cell Dimensions:	a = 13.879, b = 13.835, c = 9.942, Z = 2; V = 1,909.02 Den(Calc)= 3.22
Crystal System:	Orthorhombic - DipyramidalH-M Symbol (2/m 2/m 2/m) Space Group: Pmmn
X Ray Diffraction:	By Intensity(I/Io): 2.73(1), 2.84(1), 3.28(1),
Crystal Structure: Mouse drag1 - LMB Manipulate Structure drag2 - RMB Resize/Rotate Keyboard S - Stereo Pair on/off H - Help Screen I - Data Info A - Atoms On/Off P - Polyhedra On/Off B - Bonds On/Off Help on Above	Mazzi F , Ungaretti L , Dal Negro A , Petersen O V , Ronsbo J G , American Mineralogist , 64 (1979) p.202-210, The crystal structure of semenovite
Physical Properties of Semenovite
Cleavage:	None
Color:	Brown, Orange brown, Gray, Reddish brown, Colorless.
Density:	3.14
Diaphaniety:	Transparent to translucent
Fracture:	Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.
Habit:	Pseudo Tetragonal - Crystals show a tetragonal shape.
Habit:	Twinning Common - Crystals are usually twinned.
Hardness:	3.5-4 - Copper Penny-Fluorite
Luster:	Vitreous (Glassy)
Streak:	white
Optical Properties of Semenovite
Gladstone-Dale:	CI meas= 0.012 (Superior) - where the CI = (1-KPDmeas/KC) CI calc= 0.037 (Excellent) - where the CI = (1-KPDcalc/KC) KPDcalc= 0.1887,KPDmeas= 0.1935,KC= 0.1959
Optical Data:	Biaxial (-), a=1.595, b=1.614, g=1.614, bire=0.0190, 2V(Calc)=0, 2V(Meas)=0-55.
Calculated Properties of Semenovite
Electron Density:	relectron=3.02 gm/cc note: rSemenovite =3.14 gm/cc.
Fermion Index	Fermion Index = 0.04643 Boson Index = 0.95357
Photoelectric:	PESemenovite = 75.11 barns/electron U=PESemenovite x relectron= 226.92 barns/cc.
Radioactivity:	GRapi = 14,789.78 (Gamma Ray American Petroleum Institute Units) Semenovite is Radioactive as defined in 49 CFR 173.403. Greater than 70 Bq / gram. Estimated Radioactivity from Semenovite - weak Specimen Size Weight/Volume (Sphere) * Calculated Activity Bequerols (Bq) Calculated Activity Curies (Ci) Estimated Activity GR(api) Estimated Exposure (mRem**)/hr If Held in Hand For One Hour 1000 gm / 8.47 cm 322,792 8.72E-06 14,789.78 4.86 100 gm / 3.93 cm 32,279 8.72E-07 1,478.98 0.49 10 gm / 1.83 cm 3,228 8.72E-08 147.90 0.05 1 gm / 8.47 mm 323 8.72E-09 14.79 0.00 0.1 gm / 3.93 mm 32 8.72E-10 1.48 0.00 0.01 gm / 1.83 mm 3 8.72E-11 0.15 0.00 0.001 gm / 0.85 mm 0 8.72E-12 0.01 0.00 Weight of pure Semenovite in grams (gm) and Calculated Diameter of a Sphere with a Density of 3.14 gm/cc.* Goverment Estimate of Average Annual Exposure ( 360 mRem) ** Note: 10 microsieverts/hr = 1 mRem/hr ** Max Permissable Adult Dose 50,000 mRem/yr (hands), 15,000 mRem/yr (eyes) Lethal Dose LD(50) Exposure 400,000 to 500,000 mRem Estimated Thorium Activity ( 0.72 % Th) From Sum REE Elements (14.40 % REE)
Semenovite Classification
Dana Class:	72.5.2.4 (72)Phyllosilicate Two-Dimensional Infinite Sheets with Other Than Six-Membered Rings
	(72.5)with corrugated and complex layers
	(72.5.2)Leucospenite and related species
	72.5.2.1 Leucosphenite Na4BaTi2O2[B2Si10O28] C 2/m 2/m
	72.5.2.2 Nordite-(Ce) (Ce,La,Ca)(Sr,Ca)Na2(Na,Mn)(Zn,Mg)Si6O17 Pcca 2/m 2/m 2/m
	72.5.2.3 Nordite-(La) (Na,Mn)3(Sr,Ca)(La,Ce)(Zn,Mg)Si6O17 Pcca 2/m 2/m 2/m
	72.5.2.4 Semenovite (Na,Ca)9(Ce,La)2(Fe,Mn)(Si,Be)20(O,OH,F)48 Pmmn 2/m 2/m 2/m
	72.5.2.5 Ferronordite-(Ce)! Na3SrCeFeSi6O17 Pcca 2/m 2/m 2/m
	72.5.2.6 Manganonordite-(Ce)! Na3SrCeMnSi6O17 Pcca 2/m 2/m 2/m
	72.5.2.7 Ferronordite-(La)! Na3Sr(La,Ce)FeSi6O17 Pcca 2/m 2/m 2/m
Strunz Class:	VIII/G.03-10 VIII - Silicates
	VIII/G - Intermediate between chain- and layered silicates
	VIII/G.03 - Semenovite-(Ce) - Nordite-(La) series
	VIII/G.03-10 Semenovite (Na,Ca)9(Ce,La)2(Fe,Mn)(Si,Be)20(O,OH,F)48 Pmmn 2/m 2/m 2/m
	VIII/G.03-20 Nordite-(Ce) (Ce,La,Ca)(Sr,Ca)Na2(Na,Mn)(Zn,Mg)Si6O17 Pcca 2/m 2/m 2/m
	VIII/G.03-30 Nordite-(La) (Na,Mn)3(Sr,Ca)(La,Ce)(Zn,Mg)Si6O17 Pcca 2/m 2/m 2/m
	VIII/G.03-40 Ferronordite-(Ce)! Na3SrCeFeSi6O17 Pcca 2/m 2/m 2/m
	VIII/G.03-45 Ferronordite-(La)! Na3Sr(La,Ce)FeSi6O17 Pcca 2/m 2/m 2/m
	VIII/G.03-50 Manganonordite-(Ce)! Na3SrCeMnSi6O17 Pcca 2/m 2/m 2/m
Other Semenovite Information
References:	NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Dana8)
See Also:	Links to other databases for Semenovite : 1 -Am. Min. Crystal Structure Database 2 -Athena 3 -Google Images 4 -Google Scholar 5 -MinDAT 6 -MinMax(Deutsch) 7 -MinMax(English) 8 -Mineralienatlas (Deutsch) 9 -QUT Mineral Atlas 10 - WWW-MINCRYST Search for Semenovite using:   Web webmineral.com [ALTAVISTA] [AOL] [All-The-Web] [HotBot] [Ixquick] [MAMMA] [MSN.COM] [Netscape] [Scirus] [Teoma] [Wikipedia] [YAHOO] Visit our Advertisers for Semenovite : AA Mineral Specimens B & L Fine Minerals Crystal Vaults Dan Weinrich Fine Minerals Dan Weinrich Auctions e-Rocks Auctions Excalibur Minerals Exceptional Minerals Fabre Minerals Greenside Minerals Heliodor John Betts Fine Minerals Mason's Minerals Mineral News Mineral of the Month Club MineralsWeb Fine Minerals Rockshop.cz T G Fine Minerals Wrights Rock Shop Translate Semenovite Mineral Data : Ask about Semenovite 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 Semenovite Specimen Label here : Semenovite (Na,Ca)9(Ce,La)2(Fe++,Mn)(Si,Be)20(O,OH,F)48 Dana No: 72.5.2.4 Strunz No: VIII/G.03-10 Locality:   Notes: