Diaspore Mineral Data

General Diaspore Information

Chemical Formula:

AlO(OH)

Composition:

Molecular Weight = 59.99 gm

Aluminum 44.98 % Al 84.98 % Al₂O₃

Hydrogen 1.68 % H 15.02 % H₂O

Oxygen 53.34 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

AlO(OH)

Environment:

Metamorphic and sedimentary bauxite ores.

IMA Status:

Valid Species (Pre-IMA) 1801

Locality:

Common world wide. Link to MinDat.org Location Data.

Name Origin:

From the Greek word "to scatter," referring to the mineral's easy disintegration in the blowpipe flame.

Name Pronunciation:

Diaspore

Synonym:

ICSD 200952

PDF 5-355

Diaspore Image

Images:

Diaspore

Comments: Crystals of deep violet-colored diaspore exposed from numerous vugs.
Location: Saga Quarry, Oslo Region Norway. Scale: Crystal size 1 cm.
© John Veevaert

Diaspore Crystallography

Axial Ratios:

a:b:c =0.4667:1:0.3018

Cell Dimensions:

a = 4.397, b = 9.421, c = 2.8439, Z = 4; V = 117.81 Den(Calc)= 3.38

Crystal System:

Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: Pbnm

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 3.99(1), 2.317(0.56), 2.131(0.52),

Forms:

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Forms: ( 1 1 1) ( 0 1 0) ( 0 2 1) ( 1 1 0)

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Physical Properties of Diaspore

Cleavage:

{010} Perfect, {110} Good

Color:

White, Greenish gray, Grayish brown, Colorless, Yellow.

Density:

3.3 - 3.5, Average = 3.4

Diaphaneity:

Transparent to subtranslucent

Fracture:

Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.

Habit:

Disseminated - Occurs in small, distinct particles dispersed in matrix.

Habit:

Platy - Sheet forms (e.g. micas).

Habit:

Tabular - Form dimensions are thin in one direction.

Hardness:

6.5-7 - Pyrite-Quartz

Luminescence:

Non-fluorescent.

Luster:

Vitreous - Pearly

Streak:

white

Optical Properties of Diaspore

Gladstone-Dale:

CI meas= 0.062 (Fair) - where the CI = (1-KPDmeas/KC)
CI calc= 0.056 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2142,KPDmeas= 0.2129,KC= 0.227
Ncalc = 1.75 - 1.79

Optical Data:

Biaxial (+), a=1.7-1.702, b=1.72-1.722, g=1.747-1.752, bire=0.0470-0.0500, 2V(Calc)=80-84, 2V(Meas)=80-88. Dispersion weak, r < v.

Pleochroism (x):

colorless or colorless.

Pleochroism (y):

colorless or pale red.

Calculated Properties of Diaspore

Electron Density:

Bulk Density (Electron Density)=3.38 gm/cc
note: Specific Gravity of Diaspore =3.38 gm/cc.

Fermion Index:

Fermion Index = 0.0002585608
Boson Index = 0.9997414392

Photoelectric:

PE_Diaspore= 1.35 barns/electron
U=PE_Diaspore x rElectron Density= 4.55 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Diaspore is Not Radioactive

Diaspore Classification

Dana Class:

06.01.01.01 (06)Hydroxides and Oxides Containing Hydroxyl

(06.01)where X+++O OH

(06.01.01)Diaspore group (Orthorhombic, Pnma or Pnmd)

06.01.01.01 Diaspore AlO(OH) Pbnm 2/m 2/m 2/m

06.01.01.02 Goethite FeO(OH) Pbnm 2/m 2/m 2/m

06.01.01.03 Groutite MnO(OH) Pbnm 2/m 2/m 2/m

06.01.01.04 Montroseite (V,Fe,V)O(OH) Pbnm 2/m 2/m 2/m

06.01.01.05 Bracewellite CrO(OH) Pbnm 2/m 2/m 2/m

06.01.01.06 Tsumgallite! GaO(OH) Pbnm 2/m 2/m 2/m

Strunz Class:

04.FD.10 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate

04.F - Hydroxides (without V or U)

04.FD -Hydroxides with OH, without H2O; chains of edge-sharing octahedra

04.FD.10 Bracewellite CrO(OH) Pbnm 2/m 2/m 2/m

04.FD.10 Diaspore AlO(OH) Pbnm 2/m 2/m 2/m

04.FD.10 Guyanaite CrO(OH) Pnnm 2/m 2/m 2/m

04.FD.10 Groutite MnO(OH) Pbnm 2/m 2/m 2/m

04.FD.10 Goethite FeO(OH) Pbnm 2/m 2/m 2/m

04.FD.10 Montroseite (V,Fe,V)O(OH) Pbnm 2/m 2/m 2/m

04.FD.10 Tsumgallite! GaO(OH) Pbnm 2/m 2/m 2/m

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Diaspore

AlO(OH)
Dana No: 06.01.01.01 Strunz No: 04.FD.10
Locality:

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