n. 暗色岩

[ noun ]
any of various hard colored rocks (especially rocks consisting of chert or basalt)
<noun.object>

Whinstone \Whin"stone"\, n. [Whin + stone; cf. Scot.
quhynstane.]
A provincial name given in England to basaltic rocks, and
applied by miners to other kind of dark-colored unstratified
rocks which resist the point of the pick. -- for example, to
masses of chert. Whin-dikes, and whin-sills, are names
sometimes given to veins or beds of basalt.