Week 1998 13th. These are the sample which we saw. Most of them were as big as a hand. Some were light and others heavy.
Pumice is the ash from volcanoes.
The piece we saw looks burnt black on one side and more like white ash on the other side. Pumice is used for polishing and pumice-stones are used in the bathroom for scrubbing skin. TUFF Tuff is also made of lava but is denser and harder than pumice, but not as dense or hard as rhyolite, it is formed from flying lumps of ash blown out during an eruption. These then solidify as they fly through the air and weld together when they hit the ground. Rhyolite can be different colours and comes from the molten rock in the earth's crust called magma.