A lump of lava
(more than 32 MM across) that has been ejected from a volcano
during an eruption
s are named for their shape which is aquired in trajectory
Bread-crust bombs have a glassy crust that is criss-crossed with cracks.
Spindle bombs have a tail formed by the spinning of the bomb as it falls
- Rope bombs and ribbon bombs are twisted strands of elongated and solidified lava
- Cannonball bombs are solid, rounded lumps of lava that take shape by abrasion as they bounced to rest.