Mineralogy Database

Tobermorite Mineral Data

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General Tobermorite Information

Help on Chemical  Formula: Chemical Formula: Ca5Si6O16(OH)2•4(H2O)
Help on Composition: Composition: Molecular Weight = 702.36 gm
   Calcium   24.54 %  Ca   34.33 % CaO
   Aluminum   1.92 %  Al    3.63 % Al2O3
   Silicon   21.99 %  Si   47.05 % SiO2
   Hydrogen   1.44 %  H    12.82 % H2O
   Oxygen    50.11 %  O
            ______        ______ 
            100.00 %       97.84 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Ca4.3Si5.5Al0.5O16(OH)2•4(H2O)
Help on Environment: Environment: A hydrothermal alteration product of calcium carbonate rocks, due to contact metamorphism and metasomatism. Filling vesicles and cavities in basaltic rocks.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1880
Help on Locality: Locality: In Scotland, on the Isle of Mull, around Tobermory. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for the locality.
Help on Name Pronunciation: Name Pronunciation: Tobermorite + Pronunciation Say TOBERMORITE
Help on Synonym: Synonym: Crestmoreite - mixture with wilkeite

Tobermorite Image

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Comments: Bright white tobermorite with blue calcite, USA.
Location: Crestmore Quarry, Riverside County, California. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Tobermorite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =1.5416:1:3.0832
Help on Cell Dimensions: Cell Dimensions: a = 11.3, b = 7.33, c = 22.6, Z = 4; V = 1,871.94 Den(Calc)= 2.49
Help on Crystal System: Crystal System: Orthorhombic - Disphenoidal H-M Symbol (2 2 2) Space Group: C 2221
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 14(1), 3.706(0.65), 3.001(0.45),1.835(0.35), 2.812(0.3), 5.5(0.25), 2.793(0.13),

Physical Properties of Tobermorite

Help on Cleavage: Cleavage: {001} Perfect, {100} Imperfect
Help on Color: Color: White, Light pink white, Reddish white.
Help on Density: Density: 2.423 - 2.44, Average = 2.43
Help on Diaphaneity: Diaphaneity: Translucent
Help on Habit: Habit: Aggregates - Made of numerous individual crystals or clusters.
Help on Habit: Habit: Fibrous - Crystals made up of fibers.
Help on Habit: Habit: Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite)
Help on Hardness: Hardness: 2.5 - Finger Nail
Help on Luminescence: Luminescence: Fluorescent, Short UV=weak white to yellow, Long UV=weak white to yellow.
Help on Luster: Luster: Silky
Help on Streak: Streak: white

Optical Properties of Tobermorite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= -0.064 (Fair) - where the CI = (1-KPDmeas/KC)
CI calc= -0.039 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2297,KPDmeas= 0.2352,KC= 0.2211
Ncalc = 1.54 - 1.55
Help on Optical Data: Optical Data: Biaxial (+), a=1.57, b=1.571, g=1.575, bire=0.0050
Help on Pleochroism (x): Pleochroism (x): colorless.
Help on Pleochroism (y): Pleochroism (y): colorless.
Help on Pleochroism (z): Pleochroism (z): colorless.

Calculated Properties of Tobermorite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.52 gm/cc
note: Specific Gravity of Tobermorite =2.49 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.01
Boson Index = 0.99
Help on Photoelectric: Photoelectric: PETobermorite = 3.91 barns/electron
U=PETobermorite x rElectron Density= 9.86 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Tobermorite is Not Radioactive

Tobermorite Classification

Help on  Dana Class: Dana Class: (72)Phyllosilicate Two-Dimensional Infinite Sheets with Other Than Six-Membered Rings
  (72.03)with 3-, 4-, or 5-membered rings and 8-membered rings
  (72.03.02)Tobermorite group (5- & 8-membered rings) Tobermorite Ca5Si6O16(OH)2•4(H2O) C 2221 2 2 2 Clinotobermorite Ca5Si6(O,OH)18•5(H2O) Cc,C 2/c Mono Plombierite Ca5H2Si6O18•6H2O B11b 2 Riversideite Ca5Si6O16(OH)2•2(H2O) B2212 2 2 2 Okenite Ca3[Si6O15]•6(H2O) P1 or P1 Tri Tacharanite Ca12Al2Si18O33(OH)36 A centered Mono Nekoite Ca3Si6O15•7(H2O) P1 1 Oyelite Ca10B2Si8O29•12(H2O) B**** Ortho
Help on  Strunz Class: Strunz Class: 09.DG.10 09 - SILICATES (Germanates)
  09.D - Inosilicates* Structural terminology according to Liebau (1985)
  09.DG -Inosilicates with 3-periodic single and multiple chains
09.DG.10 Clinotobermorite Ca5Si6(O,OH)18•5(H2O) Cc,C 2/c Mono
09.DG.10 Riversideite Ca5Si6O16(OH)2•2(H2O) B2212 2 2 2
09.DG.10 Tobermorite Ca5Si6O16(OH)2•4(H2O) C 2221 2 2 2

Other Tobermorite 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 Tobermorite :
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.DG.10





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