Variolite

An old term for basaltic rocks with a pock-marked appearance, composed of variolites (radial aggregates of feldspar and pyroxene microlites) in a microcrystalline or devitrified glassy base. The variolitic texture denotes rapid cooling and the quench growth of the crystals, such as is often found in submarine basalts, and should not be confused with spherulitic texture which indicates devitrification.