If a scale and a graduated cylinder are available, the density of the tephra can be calculated. Obtain small samples of a block or bomb, cinder, pumice, and reticulite. Weigh each type of tephra on the scale. Use the amount of water displaced in the graduated cylinder to determine the volume of the sample.
Density is the mass per unit volume.
The density of solid basaltic rock is 2.65 grams per cubic centimeter. Determine the density of each sample.