Effects of interstitial water on phase transition of forsterite glass

[Display omitted] •Molecular dynamics calculations of forsterite-water systems have been performed.•Formation process of magnesium hydroxide from forsterite-water interface was analyzed.•Density of interstitial water in forsterite glass is higher than that of ordinary water.•Interstitial water plays an important role on mineral evolutions. To investigate the effects of interstitial water on phase transition mechanisms of forsterite glass, we performed molecular dynamics calculations of forsterite-water systems. The results show that the density of the interstitial water is higher than that of ordinary water. This suggests that the interstitial water can be a liquid state in forsterite glass at temperatures above the boiling point without pressurization. Furthermore, the formation of the magnesium hydroxide crystal from the dissolved MgOxHy in the high-density water was observed. The unique property of the interstitial water is an important factor to understand the evolution processes of silicate minerals in space.