What is the finest type of tephra?

Answer 1

Dust is less then 0.25 in diameter, ash is larger then dust but less then 2 mm in diameter, and the somewhat larger tephra are called lapilli which are larger than dust but less then 64 mm in diameter.

Answer 2

Ash

The smallest particle in tephra is dust

Answer 3

Volcanic Blocks (greater than 64 mm)

Lappilli ( Between 2 and 64 mm)

Ash (less than 2 mm)

Answer 4

Tephra refers to the fragments of volcanic rock and lava that are blasted into the air by explosions. The largest sized tephra is called a volcanic bomb.

Answer 5

Volcanic Ash

Answer 6

volcanic blocks :-)