Igneous Review

Andesite

Texture: aphantic

Composition: intermediate

Minerals: amphibole, olivine, biotite, quartz, plagioclase feldspar

Basalt

Texture: aphantic

Composition: Mafic

Minerals: pyroxene, olivine, plagioclase feldspar

Dirote

Texture: phaneretic

Composition: intermediate 

Minerals: pyroxene, potassium feldspar, amphibole, biotite, quartz

Gabbro

Texture: phaneretic

Composition: mafic 

Minerals: quartz, muscovite, pyroxene

Granite

Texture: phaneretic

Composition: felsic

Minerals: quartz, pottasium feldspar, biotite

Obsidian

Texture: glassy

Composition: felsic

Minerals: muscovite, silica

*volcanic glass

Pegmatite:

Texture: pegmatic

Composition: felsic

Minerals: quartz, potassium feldspar, muscovite

Peridotite

Texture: phaneretic

Composition: ultramafic

Minerals: pyroxene, olivine

Porphyritic Andesite

Porphyritic Rhyolite

Texture: porphyritic

Composition: felsic

Minerals: quartz, muscovite, potassium feldspar

Pumice

Texture: vesicular

Composition: felsic

Minerals: quartz, potassium feldspar

*soft, porous, white, yellow, gray or light pink in color

Rhyolite

Texture: aphantic

Composition: felsic

Minerals: potassium feldspar, quartz, biotite

Scoria

Texture: scoriaceous

Compostion: mafic

Minerals: iron, calcium

*volcanic rock, big holes, red/black in color

Tuff

Texture: pyroclastic

commposition: felsic

Minerals: quartz, potassium feldspar

*ash-like

Volcanic Breccia

Texture: porphyritic

Composition: felsic

Minerals: ash

*angular fragments of volcanic materials