Andesite
Rock made of plagioclase, pyroxene, hornblende
Common
A light to dark grey volcanic rock of intermediate composition, between basalt and rhyolite, named in 1826 after the Andes. The dominant rock of island arcs; the average continental crust has its composition.
Rock
- Kind of rock
- Volcanic igneous rock
- Rock family
- Volcanic rock
- Texture
- fine-grained (crystals too small to see), porphyritic (large crystals in a fine groundmass)
- How it forms
- Erupted above subduction zones, as the lava equivalent of diorite.
- Uses
- Building stone, as in the Templo Mayor and the historic buildings of Mexico City.
Crystallography
- Habits
- Massive
Physical properties
- Luster
- Dull
- Colors
- gray, dark gray
- Transparency
- Opaque
Geology
- Origins
- Volcanic
- Geography
- worldwide, Peru, Mexico
Classification
- Rarity
- Common
- Gem quality
- No
Sources
- Andesite. 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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