diabase
/ˈdaɪəˌbeɪs/
noun
- A dark gray or black igneous rock, often used in construction and road building.
- The old cobblestone street was made of diabase, which had worn smooth over the years.
- Geologists found a large deposit of diabase near the riverbed.
- The monument was carved from a single block of diabase, giving it a dark, polished look.