Pumice
Rock made of volcanic glass
Common
A foam of volcanic glass so full of bubbles that it floats: pumice rafts from undersea eruptions drift on the sea and can hinder ships. Usually pale; the dark, denser kind with bigger bubbles is scoria.
Rock
- Kind of rock
- Volcanic igneous rock
- Rock family
- Volcanic rock
- Texture
- vesicular (full of gas bubbles), glassy
- How it forms
- Superheated, pressurised magma blown out of a volcano cools and loses pressure at once, freezing the gas bubbles that come out of solution.
- Uses
- An abrasive since antiquity (skin, parchment, polish), a lightweight aggregate in concrete, and a soil amendment.
Identity
- Also known as
- Pumicite (powder)
Crystallography
- Habits
- Massive
Physical properties
- Luster
- Vitreous, Dull
- Colors
- white, gray, pale yellow
- Transparency
- Opaque
Geology
- Origins
- Volcanic
- Geography
- Italy, Turkey, Greece, Iran, Chile, Iceland, Germany
Classification
- Rarity
- Common
- Gem quality
- No
Sources
- Pumice. Wikipedia.
- M. R. Gillespie, M. T. Styles, BGS Rock Classification Scheme, Volume 1: Classification of igneous rocks (Research Report RR 99-06). British Geological Survey, 1999.
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