• journal_title：European Journal of Mineralogy
• Contributor：Thomas Fockenberg ; Michael Burchard ; Walter V. Maresch
• Publisher：E. Schweizerbart'sche Verlagsbuchhandlung Science Publishers
• Date：2008-
• Format：text/html
• Language：en
• Identifier：10.1127/0935-1221/2008/0020-1889
• journal_abbrev：Eur J Mineral
• issn：0935-1221
• volume：20
• issue：5
• firstpage：845
• section：From field observation to experimental petrology and back - A special issue to honour Werner Schreyer

The solubility of a natural grossular-rich garnet of composition Ca_2.86Fe²⁺ _0.07Mg_0.07Fe³⁺ _0.10Al_1.90Si_3.00O₁₂ has been experimentally determined in pure water at pressures from 1 to 5 GPa and temperatures ranging from 400 to 800 °C with the weight-loss technique in piston–cylinder apparatus. Grossular dissolves congruently in this pressure–temperature region. The amount of dissolved grossular increases with both increasing pressure and temperature and ranges from 0.1 to 7.0 wt.%. In comparison to available data on other phases in the CaO–Al₂O₃–SiO₂ system, the solubility of grossular is considerably lower than that of quartz (SiO₂) or wollastonite (CaSiO₃), but higher than that of corundum (Al₂O₃) at comparable pressure–temperature conditions. Using a model based on the familiar correlation between the equilibrium constant of a dissolution reaction and the density of water, ρ H₂O, we suggest that the following expression provides an acceptable description of the solubility of pure grossular, Ca₃Al₂Si₃O₁₂, in water for the above pressure–temperature range:

where m_grs is the molality of dissolved grossular and T is in °C. Uncertainties estimated from the outer bounds of experimental data scatter indicate a maximum of ±0.045 mol_grs/kg H₂O. Comparison with available experimental solubility data on quartz, wollastonite, corundum and kyanite provides indirect evidence for the presence of aqueous Al–Si-species.