Mineralogy Database

Malladrite Mineral Data

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General Malladrite Information

Help on Chemical  Formula: Chemical Formula: Na2SiF6
Help on Composition: Composition: Molecular Weight = 188.06 gm
   Sodium    24.45 %  Na   32.96 % Na2O
   Silicon   14.93 %  Si   31.95 % SiO2
   Fluorine  60.62 %  F    60.62 % F
               -   %   F   -25.52 % -O=F2    
            ______        ______ 
            100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Na2SiF6
Help on Environment: Environment: Sublimate from fumaroles.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1926
Help on Locality: Locality: Vesuvius, Italy. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for Alessandro Malladra (1865-1945), Italian volcanologist, director of the Vesuvius Observatory.
Help on Name Pronunciation: Name Pronunciation: Malladrite + Pronunciation Say MALLADRITE
Help on Synonym: Synonym: ICSD 16598
  PDF 33-1280

Malladrite Image

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  Avogadrite   Malladrite

Comments: Botryoidal pinkish-white avogadrite with yellow malladrite.
Location: Eruption of 1926, Vesuvius, Campania, Italy. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

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  Malladrite   Avogadrite

Comments: Yellow-orange crystalline malladrite with pinkish white avogadrite.
Location: Eruption of 1926, Vesuvius, Campania, Italy. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Malladrite Crystallography

Help on Axial Ratios: Axial Ratios: a:c = 1:0.5688
Help on Cell Dimensions: Cell Dimensions: a = 8.866, c = 5.043, Z = 3; V = 343.30 Den(Calc)= 2.73
Help on Crystal System: Crystal System: Trigonal - Trapezohedral H-M Symbol (3 2) Space Group: P 321
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 2.281(1), 3.325(0.8), 1.795(0.78),

Physical Properties of Malladrite

Help on Color: Color: Rose, Colorless, White.
Help on Density: Density: 2.714 - 2.755, Average = 2.73
Help on Diaphaneity: Diaphaneity: Transparent
Help on Habit: Habit: Crystalline - Fine - Occurs as well-formed fine sized crystals.
Help on Habit: Habit: Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).
Help on Hardness: Hardness: 3 - Calcite
Help on Luster: Luster: Vitreous - Greasy
Help on Streak: Streak: white

Optical Properties of Malladrite

Help on Optical Data: Optical Data: Uniaxial (-), e=1.309, w=1.313, bire=0.0040.

Calculated Properties of Malladrite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.61 gm/cc
note: Specific Gravity of Malladrite =2.73 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0069745004
Boson Index = 0.9930254996
Help on Photoelectric: Photoelectric: PEMalladrite = 1.27 barns/electron
U=PEMalladrite x rElectron Density= 3.32 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Malladrite is Not Radioactive

Malladrite Classification

Help on  Dana Class: Dana Class: (11)Halide Complexes; Alumino-fluorides
  (11.05)where (A)m B (X)6
  (11.05.02)Malladrite Group Malladrite Na2SiF6 P 321 3 2 Bararite (NH4)2SiF6 R 3m 3 2/m Demartinite! K2[SiF6] P 63mc 6mm
Help on  Strunz Class: Strunz Class: 03.CH.05 03 - HALIDES
  03.C - Complex Halides
  03.CH -
03.CH.05 Malladrite Na2SiF6 P 321 3 2

Other Malladrite Information

Help on References: References: NAME( Ford32) PHYS. PROP.(Dana8) OPTIC PROP.(Dana8)
Help on See Also: See Also: Links to other databases for Malladrite :
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: 03.CH.05





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