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Medaite Mineral Data

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General Medaite Information

Help on Chemical  Formula: Chemical Formula: (Mn,Ca)6(V+++++,As)Si5O18(OH)
Help on Composition: Composition: Molecular Weight = 827.82 gm
   Calcium     0.97 %  Ca    1.35 % CaO
   Manganese  38.49 %  Mn   49.70 % MnO
   Vanadium    4.92 %  V     8.79 % V2O5
   Silicon    16.96 %  Si   36.29 % SiO2
   Arsenic     1.81 %  As    2.78 % As2O5
   Hydrogen    0.12 %  H     1.09 % H2O
   Oxygen     36.72 %  O
             ______        ______ 
             100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Mn2+5.8Ca0.2V5+0.8As0.2Si5O18(OH)
Help on Environment: Environment: Formed at low temperatures and low H2O fugacity in veinlets cutting manganese ores.
Help on IMA Status: IMA Status: Approved IMA 1980
Help on Locality: Locality: From the Molinello manganese mine, near Chiavari, Val Graveari, Val Graveglia, Liuria, Italy. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Dr. Francesco Meda (1926-1977), an amateur mineralogist from Turin, Italy.
Help on Name Pronunciation: Name Pronunciation: Medaite Say MEDAITE
Help on Synonym: Synonym: ICSD 26908
  PDF 36-443

Medaite Image

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Comments: Orange crystalline medaite crust.
Location: Molinello Mine, near Chiavari, Liguria, Italy. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Medaite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.2318:1:0.2617
Help on Cell Dimensions: Cell Dimensions: a = 6.712, b = 28.948, c = 7.578, Z = 4; beta = 95.4° V = 1,465.86 Den(Calc)= 3.75
Help on Crystal System: Crystal System: Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 21/n
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 3.259(1), 3.159(0.83), 3.097(0.7),

Physical Properties of Medaite

Help on Cleavage: Cleavage: {100} Good, {001} Parting
Help on Color: Color: Brownish red.
Help on Density: Density: 3.7
Help on Diaphaneity: Diaphaneity: Transparent
Help on Habit: Habit: Aggregates - Made of numerous individual crystals or clusters.
Help on Habit: Habit: Granular - Generally occurs as anhedral to subhedral crystals in matrix.
Help on Luster: Luster: Subadamantine
Help on Streak: Streak: yellow white

Optical Properties of Medaite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.012 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.025 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2089,KPDmeas= 0.2117,KC= 0.2143
Ncalc = 1.79 - 1.8
Help on Optical Data: Optical Data: Biaxial (+), a=1.77, b=1.78, g=1.8, bire=0.0300, 2V(Calc)=72, 2V(Meas)=71.
Help on Pleochroism (x): Pleochroism (x): faint orange.
Help on Pleochroism (y): Pleochroism (y): pale orange.
Help on Pleochroism (z): Pleochroism (z): light orange.

Calculated Properties of Medaite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=3.55 gm/cc
note: Specific Gravity of Medaite =3.70 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0082345821
Boson Index = 0.9917654179
Help on Photoelectric: Photoelectric: PEMedaite = 12.87 barns/electron
U=PEMedaite x rElectron Density= 45.66 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Medaite is Not Radioactive

Medaite Classification

Help on  Dana Class: Dana Class: (57)Sorosilicate Insular Si3O10 and Larger Noncyclic Groups
  (57.04)with groups with 6 or more tetrahedra
  (57.04.01)Dana Group Medaite (Mn,Ca)6(V,As)Si5O18(OH) P 21/n 2/m
Help on  Strunz Class: Strunz Class: 09.BJ.30 09 - SILICATES (Germanates)
  09.B - Sorosilicates
  09.BJ -Sorosilicates with Si3O10, Si4O11, etc
09.BJ.30 Medaite (Mn,Ca)6(V,As)Si5O18(OH) P 21/n 2/m

Other Medaite Information

Help on References: References: NAME( AntBidBlaNic2) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)
Help on See Also: See Also: Links to other databases for Medaite :
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.BJ.30





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