Pumice identification and geology

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• Browse all rock identification entries — Compare this entry with the complete GeoMiner rocks collection.
• Previous: Porphyry — Igneous rock with large crystals phenocrysts set in a fine-grained groundmass. Can be of any composition.
• Next: Pyroxenite — Dark ultramafic rock composed primarily of pyroxene minerals 90% . Forms in layered intrusions.
• Scoria
• Obsidian
• Vesicular rocks — Place this specimen in a broader field-identification workflow.
• Glassy rocks — Place this specimen in a broader field-identification workflow.
• Pumice vs Scoria — Compare observable properties and safer field tests.

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

2026-03-30T14:38:11.831986+00:00

Review status

Published; not independently peer-reviewed

• Rocks — U.S. National Park Service. Authoritative overview of rock groups, the rock cycle, and geologic processes.
• Can you identify my rock or mineral? — U.S. Geological Survey. Identification limitations and routes to in-person professional verification.

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Common questions

What is Pumice?

Extremely vesicular volcanic glass so light it floats on water. Formed during explosive eruptions of silicic magma.

How can you identify Pumice?

Compare several properties rather than relying on colour alone. This entry records rock type: Igneous Extrusive; texture: Vesicular, glassy; grain size: Glassy no crystals; common minerals: Volcanic glass, Quartz minor, Feldspar minor. Confirm an important identification with additional field tests or qualified laboratory work.

How does Pumice form?

Forms when gas-rich silicic magma is rapidly depressurized during explosive eruptions, creating a froth of glass.

Where is Pumice commonly found?

Worldwide volcanic regions; commercially from Italy, Greece, USA, Turkey. Floats on water.

What is Pumice commonly confused with?

Pumice may be confused with Scoria, Volcanic Tuff, Obsidian. Compare multiple diagnostic properties because colour and surface appearance can overlap.