(n.) A soft, earthy, dark-colored rock or clay derived from the alteration of basalt.

abnormal absurd anomalous apish asinine balmy bananas barmy bats batty beany befooled beguiled besotted bonkers brainless buffoonish buggy bughouse bugs cockeyed cracked crackers crank crankish cranky crazed crazy credulous crotchety cuckoo daffy daft dazed demented deranged deviant deviative different dippy divergent dizzy doting dotty dumb eccentric erratic exceptional fatuitous fatuous fey flaky flipped fond fool foolheaded foolish freaked-out freakish fruitcakey fruity fuddled funny futile gaga goofy gulled harebrained haywire idiocratic idiosyncratic idiotic imbecile inane inept infatuated insane irregular just plain nuts kinky kooky loony loopy lunatic mad maggoty maudlin moronic nuts nutty odd oddball off the hinges off the track off the wall peculiar potty preposterous queer quirky round the bend sappy screwball screwballs screwy senseless sentimental silly singular slaphappy strange stupid thoughtless twisted unconventional unnatural wet whimsical witless