Exploring Rocks and Minerals: Pumice

What is PMU?

Understanding PMU and Its Characteristics

• PMU, or pumice, is classified as an extrusive vesicular igneous rock formed from rapidly cooling lava after a volcanic eruption.

• The term "vesicular" indicates that pumice contains air bubbles or gas pockets trapped during the rapid solidification process, giving it a rough texture.

• Pumice is primarily composed of minerals such as feldspar, augite, hornblende, and zircon; however, there are various types of pumice and related vesicular rocks like scoria and vesicular basalt.

• Due to its unique vesicular texture, pumice has a low density that allows it to float on water—making it one of the only known rocks capable of floating because its density is lower than that of water.