| Rock class: | Hypabyssal Igneous Rock |
| Composition: | Plagioclase (labradorite-bytownite and clinopyroxene), with others. |
| Color: | Black, Dark green |
| Fracture: | Conchoidal (varies) |
| Specific Gravity: | 10 |
| Environment: | Often found in extensive sills and dikes; may vary in appearance at a single site due to differential cooling rates and other localized conditions. |
| Uses: | Building stone. |
| Comments: | Notable locations include the Karroo in southern Africa and a Triassic in New Jersey. Sometimes found in association with copper minerals. |