Cristobalite(beta)

Formula : SiO2

Family: 
Space group: 
Tetragonal - Trapezohedral HM symbol (4 2 2) Space Group: P 41212
Dana class: 
75.1.1.1
High temperature: 
Above approximately 1470C to the melting point of silica round 1713C.
Geological context: 
Present in volcanic rocks, it form from molten rock at temperatures above approximately 1470 degrees Celsius to the melting point of silica (around 1713C)

Dernière mise à jour le 25.01.2021

THERMODYNAMICS

Reaction properties

Cristobalite(beta) + 2H2O ⇌ H4SiO4

298.15 K, 1 bar log10K: -3.10 ΔH°r: J·mol-1 (Ref.: )
T(°C) 0 25 60 100 150 200 250 300
log10K -3.45 -3.10 -2.78 -2.52 -2.28 -2.09 -1.94 -1.82