Intrusive Slow Cooling Extrusive Fast Cooling

Texture Coarse Grained Syenite Granite Fine Grained Trachyte Rhyolite Glassy or Frothy Pumice Obsidian Felsic < 25% Dark Minerals Texture Coarse Grained Diorite Fine Grained Andesite Glassy  or  Frothy Intermediate 25-50% Dark Minerals Texture Coarse Grained Gabbro Fine  Grained Basalt Glassy  or  Frothy Scoria Mafic Dark Minerals Dominate Temperature of Mineral Formation 600 C 900 C Increasing Density