Agglomerate (from the Latin agglomerare meaning "to form into a ball") is a coarse accumulation of large blocks of volcanic material that contains at least 75% bombs. Volcanic bombs differ from volcanic blocks in that their shape records fluidal surfaces: they may, for example, have ropy, cauliform, scoriaceous, folded, spindle, spatter, ribbon, ragged, or amoeboid shapes. Globular masses of lava may have been shot from the crater at a time when partly molten lava was exposed, and was frequently shattered by sudden outbursts of steam. These bombs were viscous at the moment of ejection and by rotation in the air acquired their shape. They are commonly 1 to 2 feet (30 to 60 cm) in diameter, but specimens as large as 12 feet (3.7 m) have been observed. There is less variety in their compositi