verb. 1  To take (the property of another) without right or permission. 2  To present or use (someone else's words or ideas) as one's own. 3  To get or take secretly or artfully: steal a look at a diary; steal the puck from an opponent. 4  To give or enjoy (a kiss) that is unexpected or unnoticed.
Peridotite is a coarse-grained, dark-colored intrusive igneous rock, which consists of minerals such as pyroxene and olivine. It usually contains olivine as the primary mineral in addition to other mafic minerals, such as amphiboles and pyroxenes. It is very low in silica and high in magnesium.
Igneous rocks are classified according to their mineral content: Ultramafic rocks are dominated by olivine and/or pyroxene. Mafic rocks are dominated by plagioclase and pyroxene (even if you can't see them with the naked eye) and smaller amounts of olivine. Intermediate rocks are roughly even mixtures of felsic minerals (mainly plagioclase) and mafic minerals (mainly hornblende, pyroxene, and/or biotite).