Explanation
Commonly known as pumice, it is a porous acidic extrusive rock. It is characterized by many pores (porosity up to 40% -70%), low density (density 0.3-0.4g/cm3), and can float above the water surface. It looks like slag, white and gray. All vitreous texture, pore structure. The chemical composition is equivalent to that of rhyolite.
Classification
Natural materials and products -> Mineral materials