[dahy-uh-beys] 
| 1. | a fine-grained gabbro occurring as minor intrusions. |
| 2. | British. a dark igneous rock consisting essentially of augite and feldspar; an altered dolerite. |
| di·a·base (dī'ə-bās') n. A dark-gray to black, fine-textured igneous rock composed mainly of feldspar and pyroxene and used for monuments and as crushed stone. [French, partly from Greek diabasis, a crossing over (from diabainein, to pass through or over; see diabetes) and partly from diabase (dia-, two alteration of di-, from Greek di-; see di-1 + base, basis from Old French; see base1).] |
| diabase (dī'ə-bās') Pronunciation Key
A dark-gray to black, medium-grained igneous rock consisting mainly of labradorite and pyroxene. Diabase is compositionally similar to andesite, but has coarser grains. It is commonly found in sills and dikes. Also called dolerite. |
əˌbeɪs