Lava with a jagged surface
Aa
Very slow creeping lava
Pahoehoe
Large round lumps of lava formed from underwater volcanos
Pillow lava
Large block of rock shot out of a volcano
Block lava
Blobs of magma cooled in air
Volcanic bombs
Little stone sized pieces
Lapilli
Tiny pebble sized
Cinders
Extremely fine dust
Volcanic ash