The amethyst-throated mountaingem (Lampornis amethystinus), also called amethyst-throated mountain-gem or amethyst-throated hummingbird, is a species of hummingbird in tribe Lampornithini of subfamily Trochilinae. It is found in El Salvador, Guatemala, Honduras, and Mexico.
Adult males of the nominate subspecies have a dark green crown and back, a bronze rump, and blackish uppertail coverts. The tail is black with gray tips on the outer feathers. It has a brilliant rosy pink gorget. The breast and belly are dusky gray and the undertail coverts pale buff. The female is almost the same but has a cinnamon throat. Juveniles are similar to females but males may have a few pink feathers on the throat.