A cinder is a pyroclastic material (lava or magma). Cinders are either intrusive igneous (magma cooled inside the earth) or extrusive igneous (lava cooled outside of the earth).
A cinder is a pyroclastic material (lava or magma). Cinders are either intrusive igneous (magma cooled inside the earth) or extrusive igneous (lava cooled outside of the earth).