| Rock class: | Igneous Rock |
| Composition: | Ferromagnesian, high in MgO and FeO + Fe3O3. Content varies in accessory and secondary minerals |
| Hardness: | highly variable, avg. 5.5-6 |
| Luster: | randomly oriented crystals create mottling luster |
| Color: | Dull green to black. Olivine-based dunite, a variety of peridotite, is light green to yellowish green |
| Cleavage: | numerous surfaces |
| Fracture: | irregular |
| Grain: | med.-coarse |
| Crystal form: | random, depends on minerals present |
| Environment: | Occurs as dikes, sills, laccoliths, and stocks. Forms at depth, by the slow cooling and crystallization of a magma of ferromagnesian silicate. Extrusive rocks of peridotite are rare. |
| Uses: | source of chromite, nickel ore, native platinum; diamond is mined from mica peridotite. |
| Comments: |