Diaspore

Formula : AlO(OH)

Space group: 
Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: Pbnm
Dana class: 
6.1.1.1 (6)Hydroxides and Oxides Containing Hydroxyl (6.1)where X+++O OH (6.1.1)Diaspore group (Orthorhombic, Pnma or Pnmd)
High temperature: 
From the ambiant to 450C in metamorphic terranes
Geological context: 
Major constituent of most bauxite ores that are secondary deposits from supergene alteration.

Dernière mise à jour le 11.06.2018

THERMODYNAMICS

Individual properties (298.15 K)
M
g·mol-1
cm3·mol-1
ΔGºf
J·mol-1
ΔHºf
J·mol-1
J·mol-1·k-1
CP
J·mol-1·K-1
59.988 17.760 -922740 -1001300 35.300 53.33
Reaction properties

Diaspore + 3H+ ⇌ Al+3 + 2H2O

298.15 K, 1 bar log10K: 6.87 ΔH°r: -108760 J·mol-1
T(°C) 0 25 60 100 150 200 250 300
log10K 8.60 6.87 4.86 3.01 1.16 -0.38 -1.73 -2.98