Supplies pumice aggregates used to produce lightweight concrete building materials. Pumice - Suppliers of pumice, lightweight concrete, lightweight backfill, lightweight aggregate and pre-cast block products. Pumice is a light, porous igneous rock that is formed during volcanic eruptions. The texture of pumice resembles a sponge with its many hollows and cavities. Because of its porous nature, pumice is a lightweight material that is an ideal replacement for heavyweight concrete products. Lightweight pumice aggregate can reduce the weight of precast by up to one-half. Since its development in the early nineteen hundreds, Pumice structural lightweight concrete has been used extensively in high-rise buildings, commercial buildings, hospitals, schools, government housing and major shopping centers.