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Megacyclite Mineral Data

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General Megacyclite Information

Help on Chemical  Formula: Chemical Formula: Na8KSi9O18(OH)9•19(H2O)
Help on Composition: Composition: Molecular Weight = 1,250.12 gm
   Potassium   3.13 %  K     3.77 % K2O
   Sodium     14.71 %  Na   19.83 % Na2O
   Silicon    20.22 %  Si   43.26 % SiO2
   Hydrogen    3.71 %  H    33.14 % H2O
   Oxygen     58.23 %  O
             ______        ______ 
             100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Na8KSi9O18(OH)9•18.5(H2O)
Help on Environment: Environment: In unweathered ultra-alkalic pegmatites in an alkalic massif. Turns white on exposure to air.
Help on IMA Status: IMA Status: Approved IMA 1993
Help on Locality: Locality: On Mt. Rasvumchorr, Khibiny massif, Kola Peninsula, Russia. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: From the Greek for large and cyclical, with reference to the large ringlike groups of silica tetrahedra in the structure.
Help on Name Pronunciation: Name Pronunciation: Megacyclite + Pronunciation Say MEGACYCLITE
Help on Synonym: Synonym: IMA1991-015

Megacyclite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =2.0862:1:1.2495
Help on Cell Dimensions: Cell Dimensions: a = 24.91, b = 11.94, c = 14.92, Z = 4; beta = 94.47° V = 4,424.09 Den(Calc)= 1.88
Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 21/c
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 3.08(1), 2.938(0.7), 2.64(0.6),4.26(0.6), 2.289(0.35), 2.4(0.35), 7.42(0.2),

Physical Properties of Megacyclite

Help on Cleavage: Cleavage: {100} Perfect, {001} Good
Help on Color: Color: Colorless, White.
Help on Density: Density: 1.82
Help on Diaphaneity: Diaphaneity: Transparent
Help on Fracture: Fracture: Regular - Flat surfaces (not cleavage) fractured in a regular pattern.
Help on Habit: Habit: Irregular Grains - Occurs as splotchy, anhedral crystals forming inclusions in other minerals or rocks.
Help on Hardness: Hardness: 2 - Gypsum
Help on Luster: Luster: Vitreous - Dull
Help on Streak: Streak: white

Optical Properties of Megacyclite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.049 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= -0.016 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2516,KPDmeas= 0.2599,KC= 0.2477
Ncalc = 1.45 - 1.47
Help on Optical Data: Optical Data: Biaxial (-), a=1.46, b=1.478, g=1.481, bire=0.0210, 2V(Calc)=44, 2V(Meas)=44. Dispersion r > v strong.

Calculated Properties of Megacyclite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=1.93 gm/cc
note: Specific Gravity of Megacyclite =1.88 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0097313629
Boson Index = 0.9902686371
Help on Photoelectric: Photoelectric: PEMegacyclite = 1.40 barns/electron
U=PEMegacyclite x relectron= 2.70 barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 46.44 (Gamma Ray American Petroleum Institute Units)
Concentration of Megacyclite per GRapi unit = 2.15 (%)

Estimated Radioactivity from Megacyclite - barely detectable


Megacyclite Classification

Help on  Dana Class: Dana Class: (62)Cyclosilicate Eight-Membered Rings
  (62.01)with 8-memebered and larger rings
  (62.01.02)Dana Group Megacyclite Na8KSi9O18(OH)9•19(H2O) P 21/c 2/m
Help on  Strunz Class: Strunz Class: 09.CP.10 09 - SILICATES (Germanates)
  09.C - Cyclosilicates
  09.CP -12-membered and larger rings
09.CP.10 Megacyclite Na8KSi9O18(OH)9•19(H2O) P 21/c 2/m

Other Megacyclite Information

Help on References: References: NAME( AntBidBlaNic2) PHYS. PROP.(AntBidBlaNic2) OPTIC PROP.(AntBidBlaNic2)
Help on See Also: See Also: Links to other databases for Megacyclite :
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.CP.10





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