diabase

noun

di·​a·​base ˈdī-ə-ˌbās 

1

archaic : diorite

2

chiefly British : an altered basalt

3

: a fine-grained rock of the composition of gabbro but with an ophitic texture

diabasic

ˌdī-ə-ˈbā-sik 

adjective

Examples of diabase in a Sentence

Recent Examples on the Web

It’s made of diabase traprock, which contains iron that causes the cliffs to look lumpen and rusty in the wrong light, precise and resplendent in the right one. —Christian Wiman, Harper's magazine, 20 Jan. 2020

Word History

Etymology

French, probably from Greek diabasis act of crossing over, from diabainein to cross over, from dia- + bainein to go — more at come

First Known Use

1811, in the meaning defined at sense 1