| Rock class: | Intrusive Igneous Rock |
| Composition: | Plagioclase and others. |
| Color: | Black, Dark grey |
| Specific Gravity: | 10 |
| Grain: | Coarse |
| Uses: | Building stone, polished slabs. |
| Comments: | Diorite once was used for many rocks which are now called by other names. For example, Diorite Porphyry (sp. grav. = 5, gray, green, or reddish) includes hornblende and biotite and quartz as well as plagioclase, and is a hypabyssal igneous rock commonly found in association with granite plutons and dikes (as in Scotland). |