Lapilli: Bokstavelig: "små steiner." Runde til avlange
fragmenter av fjell/stein, som måler fra 2.5mm til 1 cm
i diameter, og som blir kastet ut fra vulkanen enten
i fast eller myk/flytende form.
1. Fragments of lava or rock between 2 and 64 millimeters in size
that are blasted into the air by volcanic explosions
2. Rock fragments between 2 and 64 mm (0.08-2.5 in) in diameter that
were ejected from a volcano during an explosive eruption are
called lapilli. Lapilli (singular: lapillus) means "little stones"
in Italian. Lapilli may consist of many different types
of tephra, including scoria, pumice, and reticulite. Rounded tephra
particles in this size range are called accretionary lapilli
if they consist of tiny ash grains stuck together. Ash sometimes form
such rounded particles in an eruption column or cloud,
owing to moisture or electrostatic forces.