Gabbro
A mafic rock in which quartz is rare. Gabbro is poorer in silica than granite (about 50 percent by weight) and is composed essentially of calcic plagioclase, pyroxene (usually augite), olivine, and magnetite.
TEXTURE Gabbro is a coarse-grained and equigranular rock.
ORIGIN Forms in major plutonic intrusions, which are commonly layered.
Group: IGNEOUS
Origin: Intrusive
Grain size: Coarse
Crystal shape: Euhedral
Classification: Mafic
Occurrence: Pluton
Color: Medium
