n.
Coarse-grained, heavy, igneous rock that contains at least 10% olivine , other iron-and magnesium-rich minerals (generally pyroxenes ), and not more than 10% feldspar .
Peridotite is the ultimate source of all chromium ore and naturally occurring diamonds , and of nearly all chrysotile asbestos. Nearly all peridotite is more or less altered to serpentine ; in warm, humid climates peridotite and serpentine have weathered to soils and related deposits that, though now worked on a relatively small scale, are potential sources of iron, nickel, cobalt, and chromium.