Scoria
Scoria is the vesicular ejecta of mafic lavas. Mafic simply means
that the lava or magma is rich in iron and magnesium and poor in silica.
Scoria is commonly in the size range of lapilli to bombs and is black,
red, or brown in color. Because basalt, a mafic lava or rock, is the
most common type of lava in Hawaii, scoria is a good general term for
most Hawaiian tephra. Photo by Steve Mattox, June, 1995.
