Pumice or Scoria

Physical Properties

Highly vesicular (porous) texture, light color (if pumice) or darker (if scoria), relatively low density, rough texture.

Formation & Geological History

Formed from gas-rich, frothy magma that cools rapidly during an explosive volcanic eruption, trapping gas bubbles (vesicles).

Uses & Applications

Used as an abrasive, in lightweight aggregate for concrete, and as landscaping material.

Geological Facts

Pumice can be so light that it floats on water due to its high porosity.

Field Identification & Locations

Identifiable by its sponge-like appearance and light weight. Commonly found near active or extinct volcanic regions.

Identified on: 4/26/2026

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