Common Igneous Rocks (Part 6)
Scoria
Scoria is an igneous rock with vesicular texture. The vesicles, or holes, in the rock form from bubbles of volcanic gas. Scoria forms the crust of lava flows.
Scoria (Photograph by Parvinder Sethi)
Pumice
Pumice is another volcanic igneous rock with vesicular texture. Pumice is less dense and lighter colored than scoria. It is commonly identified by its scratchy surface and low density.
Pumice (Photograph by Phyllis Newbill)