Igneous Rock Review

Granite – Igneous -phaneritic -felsic (low contain of heavy and dark minerals)

Diorite – Igneous -phaneritic -andesitic -medium amount of heavy and dark minerals

Gabbro -phaneritic -mafic appearnace…..high content of dark and heavy minerals

Rhyolite -Aphanitic -fined grained crystals -felsic

Andesite -aphanitic -fine grain size -andesitic in color

Basalt -aphanitic -mafic (high content of iron/magnesium/heavy minerals -found @ the bottom of the ocean

Pumice -vesicular (holy rock) -high content of light colored silicates -will float in water

Scoria -vesicular (holy rock) -mafic (high content of iron/magnesium/ heavier minerals -will not float in water

Obsidian -glass or extremely aphanitic -called “volcanic glass”

Porphyritic Granite -aphanitic and phaneritic -2 cooling rates

Pegmatite Granite -extremely large crystals (super slow cooling rate)