Mid-Ocean Ridge Basalt is a big deal for hard rock geologists. (When I write hard rock geologists, I am not referring to geologists fond of loud, distorted electric guitar tones. Rather, I am using a somewhat archaic term that differentiates igneous and metamorphic petrologists from those who study softer, sedimentary rocks.)
Mid-Ocean Ridge Basalt is a rock that forms at the mid-ocean ridge when magma from the mantle leaks to surface and cools—the innards of the world spilling forth, the Earth's rocky blood bleeding out and scabbing over.
I like to think that somewhere in the world, maybe in Boston, there is a bar. But it's not just any bar. It's a bar where all the patrons are different types of rock. And when Mid-Ocean Ridge Basalt walks in, they all yell, "MORB!"