Planet Earth Lab - Igneous

granite

• phaneritic (coarse grained)

• quartz, k-feldspar (pink), biotite

• felsic

• intrusive

peridotite

• phaneritic

• mineral: olivine

• color index: ultramafic

• intrusive

granite

• pegmatic

• quartz, plagioclase feldspar

• felsic

• intrusive

Andesite

• porphyritic

• plagioclase felspar

• mafic

• extrusive

Obsidian

• glassy

• No minerals

• no color index?

• extrusive

rhyolite

• porphyritic

• quartz, k-feldspar

• felsic

• intrusive

gabbro

• phaneritic

• mineral: pyroxene, quartz

• mafic

• intrusive

basalt

• aphanitic

• iron & magnesium rich

• mafic

• extrusive

pumice

• vesicular

• muscovite mica (brown)

• felsic

• extrusive (small bubbles caused by gas)

volcanic breccia

• porphyritic

• k-feldspar

• intermediate color

• extrusive

Diorite

• phaneritic

• plagioclase feldspar, biotite

• intermediate

• intrusive

scoria

• vesicular

• minerals: N/A

• mafic

• extrusive

volcanic tuff

• phaneritic

• minerals: N/A

• Felsic

• extrusive

granite

• phaneritic

• k-feldspar (pink), brown mica

• felsic

• intrusive

basalt

• aphanitic

• minerals: not visible

• mafic

• extrusive