dol·er·ite 
(dŏlə-rīt′)
(dŏlə-rīt′)n.
Chiefly British
Chiefly British
A dark, fine-grained igneous rock; diabase.
[French dolérite, from Greek doleros, deceitful (from its easily being mistaken for diorite), from dolos, trick; see del-2 in the Appendix of Indo-European roots.]
dol′er·itic (ə-rĭtĭk) adj.