Mineral Spotlight - Pumice

The term pumice refers to any volcanic igneous rock that was erupted as liquid but cooled so rapidly that crystallisation does not occur. It is therefore composed entirely of small glass bubbles formed when contained gases were suddenly released. The vesicular texture gives pumice unique characteristics including lightweight, thermal and acoustic insulatory properties, and mechanical strength. In addition, it is inert and heat resistant. The weight and strength factors are particularly important in its largest consuming market - structural blocks - where as an aggregate addition it provides considerable costs savings.