Diabase tends to be found in long vertical sheets called dikes that cut through other, more common continental rocks. Diabase dikes are found all along the East Coast of North America.

How do I know if I have diabase?

Diabase is best identified in thin section with a petrographic microscope, with x-ray diffraction, or with other instruments that can identify the component minerals and their relative abundances.

What kind of rock is diabase?

Diabase is an intrusive igneous rock with the same mineral composition as basalt.