Pumice  /ˈpʌmɨs/ is a textural term for a volcanic rock that is a solidified frothy lava typically created when super-heated, highly pressurized rock is violently ejected from a volcano. It can be formed when lava and water are mixed. This unusual formation is due to the simultaneous actions of rapid cooling and rapid depressurization. The depressurization creates bubbles by lowering the solubility of gases (including water and CO₂) dissolved in the lava, causing the gases to rapidly exsolve (like the bubbles of CO₂ that appear when a carbonated drink is opened). The simultaneous cooling and depressurization freezes the bubbles in the matrix.