Pumice

Pumice is a type of extrusive volcanic rock, produced when lava with a very high content of water and gases is discharged from a volcano. As the gas bubbles escape, the lava becomes frothy.  When this lava cools and hardens, the result is a very light rock material filled with tiny bubbles of gas.  Commonly it is light-colored, indicating that it is a volcanic rock high in silica content and low in iron and magnesium, a type usually classed as rhyolite.

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Description

Pumice is a type of extrusive volcanic rock, produced when lava with a very high content of water and gases is discharged from a volcano. As the gas bubbles escape, the lava becomes frothy.  When this lava cools and hardens, the result is a very light rock material filled with tiny bubbles of gas.  Commonly it is light-colored, indicating that it is a volcanic rock high in silica content and low in iron and magnesium, a type usually classed as rhyolite.

Relation to Mining

Pumice is mined through open pit and quarrying methods. Extraction and processing methods vary, depending on the end use. It can be cut into blocks or crushed.

Uses

Pumice is used to make lightweight construction materials such as concrete block and concrete.

The remainder of the pumice mined is used in abrasives (for personal care, industrial cleaners, rubber erasers, stonewashing jeans, etc.) absorbents (potting soil, pet litter, etc.), and architecture (insulation, roofing, landscaping, etc.)