Figure 4
From: Water-carbon dioxide solid phase equilibria at pressures above 4 GPa
Photomicrograph of crystals growing from a water-CO2 fluid at 240 °C and 6.5 GPa. Crystals “a” and “b” are both of phase S3 and were observed to fall through the fluid. At first “b” was clear, but then abruptly darkened, presumably as trapped fluid (non-stoichiometric relative to S3) precipitated crystallites of the H2O(VII)-S3 eutectic. Crystals “c” are H2O(VII) which floated up through the fluid.
