Andesite

Rock group Igneous
Classification Extrusive/volcanic
Composition Intermediate
Texture Aphanitic
Porphyritic
Intrusive counterpart Diorite
Common minerals Plagioclase feldspar
Pyroxene
Hornblende

Andesite in Hand Sample

Campus andesite from El Paso, TX
Porphyritic andesite
Porphyritic andesite from the summit of Mt. Kilimanjaro
Porphyritic andesite from the Crazy Mountains, MT
Beartooth andesite

Andesite in Thin Section

Thin Section GigaPans

Porphyritic andesite, plane polars
Porphyritic andesite, crossed polars

Porphyritic andesite, plane polars

Porphyritic andesite, plane polars

Porphyritic andesite in plane polarized light. Magnification: 40x Click here for crossed polars: Click here to explore this slide in plane polars: https://vi…

Porphyritic andesite, crossed polars

Porphyritic andesite, crossed polars

Porphyritic andesite in cross polarized light. Magnification: 40x Click here for plane polars: https://youtu.be/hO28wMy0wu0 Click here to explore this slide …