norite

thumb|right|Sample of norite thumb|right|Shocked norite found in the Taurus-Littrow valley on the moon during the [[Apollo 17 mission (sample 78236).]] Norite is a mafic intrusive igneous rock composed largely of the calcium-rich plagioclase labradorite, orthopyroxene, and olivine. The name norite is derived from Norway, by its Norwegian name Norge.

Norite, also known as orthopyroxene gabbro, may be essentially indistinguishable from gabbro without thin section study under the petrographic microscope. The principal difference between norite and gabbro is the type of pyroxene of which it is composed. Norite is predominantly composed of orthopyroxenes, largely high-magnesian enstatite or an iron-bearing hypersthene. The principal pyroxenes in gabbro are clinopyroxenes, generally iron-rich augites.