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Pumice identification and geology

A highly vesicular, low-density volcanic glass formed during explosive eruptions of viscous, gas-rich felsic or intermediate magma. The rapid expansion and release of dissolved gases creates a frothy, sponge-like texture with so many gas bubbles vesicles that pumice typically floats on water. Pumice is light-colored white to gray , with a silica content typically exceeding 63%. Field: volcanology. Example: After the 1883 eruption of Krakatau, floating rafts of pumice covered vast areas of the Indian Ocean, some large enough to support vegetation, and drifted for months before eventually waterlogging and sinking.. Related terms: Vesicular, Scoria, Rhyolite, Pyroclastic.

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  • Scoria
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Sources, scope & corrections

These authoritative resources support category-level nomenclature, terminology, identification methods, and safety. When a specimen-specific safety warning appears, the public-health source listed here directly supports that precaution. They are not line-by-line citations for every other property on this entry, and natural specimens vary.

Editorial owner
GeoMiner
Last updated
2026-03-30T15:19:42.055955+00:00
Review status
Published; not independently peer-reviewed
  • USGS Thesaurus — U.S. Geological Survey. Controlled earth-science terminology used to describe USGS information resources.
  • Glossary of Geologic Terms — U.S. National Park Service. Geologic definitions prepared by the NPS Geologic Resources Inventory.

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Common questions

What does Pumice mean in geology?
A highly vesicular, low-density volcanic glass formed during explosive eruptions of viscous, gas-rich felsic or intermediate magma. The rapid expansion and release of dissolved gases creates a frothy, sponge-like texture with so many gas bubbles vesicles that pumice typically floats on water. Pumice is light-colored white to gray , with a silica content typically exceeding 63%.
What is an example of Pumice?
After the 1883 eruption of Krakatau, floating rafts of pumice covered vast areas of the Indian Ocean, some large enough to support vegetation, and drifted for months before eventually waterlogging and sinking.
Which earth-science field uses the term Pumice?
Pumice is used in volcanology.
Which terms are related to Pumice?
Related terms in this reference are Vesicular, Scoria, Rhyolite, Pyroclastic.

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