Mineralogy Database

Gibbsite Mineral Data

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General Gibbsite Information

Help on Chemical  Formula: Chemical Formula: Al(OH)3
Help on Composition: Composition: Molecular Weight = 78.00 gm
   Aluminum  34.59 %  Al   65.36 % Al2O3
   Hydrogen   3.88 %  H    34.64 % H2O
   Oxygen    61.53 %  O
            ______        ______ 
            100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: Al(OH)3
Help on Environment: Environment: Lateritic soils developed on aluminous rocks in areas of high rainfall.
Help on IMA Status: IMA Status: Valid Species (Pre-IMA) 1822
Help on Locality: Locality: Bauxite deposits of Arkansas, USA. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named after the American collector, G. Gibbs (1776-1833).
Help on Name Pronunciation: Name Pronunciation: Gibbsite Say GIBBSITE
Help on Synonym: Synonym: Hydrargyllite
  ICSD 36233
  PDF 33-18
 

Gibbsite Image

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  Gibbsite

Comments: Transparent to white, tabular-prismatic gibbsite crystals.
Location: Saga Quarry, Langesundfjord, Oslo Region, Norway. Scale: Crystal size 1 mm.
© John Veevaert

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  Doyleite   Gibbsite

Comments: Botryoidal spheres of doyleite growing along with its dimorph gibbsite. Analysis shows that doyleite dominates the mix. There are also minor canary yellow phlogopite crystals.
Location: Baoshan, Yunnan, China. Scale: 8 x 6.5 x 1.9 cm.
© Fabre Minerals

Gibbsite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =1.7043:1:1.9169
Help on Cell Dimensions: Cell Dimensions: a = 8.641, b = 5.07, c = 9.719, Z = 8; beta = 94.566° V = 424.44 Den(Calc)= 2.44
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): 4.82(1), 4.34(0.4), 4.3(0.2),
 

Physical Properties of Gibbsite

Help on Cleavage: Cleavage: {001} Perfect
Help on Color: Color: Bluish, Green, Green white, Gray, Gray white.
Help on Density: Density: 2.3 - 2.4, Average = 2.34
Help on Diaphaneity: Diaphaneity: Translucent to transparent
Help on Fracture: Fracture: Tough - Difficult to break apart as shown by fibrous minerals and most metals.
Help on Habit: Habit: Earthy - Dull, clay-like texture with no visible crystalline affinities, (e.g. howlite).
Help on Habit: Habit: Spherical - Spherical, rounded aggregates.
Help on Habit: Habit: Stalactitic - Shaped like pendant columns as stalactites or stalagmites (e.g. calcite).
Help on Hardness: Hardness: 2.5-3 - Finger Nail-Calcite
Help on Luminescence: Luminescence: Non-fluorescent.
Help on Luster: Luster: Vitreous - Pearly
Help on Streak: Streak: white
 

Optical Properties of Gibbsite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.033 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= 0.069 (Fair) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2356,KPDmeas= 0.2446,KC= 0.2531
Ncalc = 1.58 - 1.62
Help on Optical Data: Optical Data: Biaxial (+), a=1.568-1.57, b=1.568-1.57, g=1.586-1.587, bire=0.0170-0.0180, 2V(Calc)=0, 2V(Meas)=0-5. Dispersion r > v or r < v.
Help on Pleochroism (x): Pleochroism (x): colorless.
Help on Pleochroism (y): Pleochroism (y): colorless.
 

Calculated Properties of Gibbsite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.41 gm/cc
note: Specific Gravity of Gibbsite =2.35 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.0003011748
Boson Index = 0.9996988252
Help on Photoelectric: Photoelectric: PEGibbsite = 1.10 barns/electron
U=PEGibbsite x rElectron Density= 2.65 barns/cc.
Help on Radioactivity: Radioactivity: GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Gibbsite is Not Radioactive
 

Gibbsite Classification

Help on  Dana Class: Dana Class: 06.03.01.01 (06)Hydroxides and Oxides Containing Hydroxyl
  (06.03)with (OH)3 or (OH)6 groups
  (06.03.01)Dana Group
 
06.03.01.01 Gibbsite Al(OH)3 P 21/n 2/m
Help on  Strunz Class: Strunz Class: 04.FE.10 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate
  04.F - Hydroxides (without V or U)
  04.FE -Hydroxides with OH, without H2O; sheets of edge-sharing octahedra
 
04.FE.10 Bayerite Al(OH)3 P 21/a 2/m
 
04.FE.10 Doyleite Al(OH)3 P1 1
 
04.FE.10 Gibbsite Al(OH)3 P 21/n 2/m
 
04.FE.10 Nordstrandite Al(OH)3 P1 1
 

Other Gibbsite Information

Help on See Also: See Also: Links to other databases for Gibbsite :
1 - Alkali-Nuts(English)
2 - Alkali-Nuts(Francais)
3 - Am. Min. Crystal Structure Database
4 - Amethyst Galleries' Mineral Gallery
5 - Athena
6 - EUROmin Project
7 - Ecole des Mines de Paris
8 - GeoScienceWorld
9 - Google Images
10 - Google Scholar
11 - Handbook of Mineralogy (MinSocAm)
12 - Handbook of Mineralogy (UofA)
13 - MinDAT
14 - Mineralienatlas (Deutsch)
15 - Online Mineral Museum
16 - QUT Mineral Atlas
17 - Ruff.Info
18 - University of Colorado - Mineral Structure Data
19 - WWW-MINCRYST

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Print or Cut-and-Paste your Gibbsite Specimen Label here :

Gibbsite

Al(OH)3
Dana No: 06.03.01.01 Strunz No: 04.FE.10
Locality:

 

Notes:

 

 


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