Black Amazon of Mars by Leigh Brackett

Grimly Eric John Stark slogged toward that ancient Martian city—with every step he cursed the talisman of Ban Cruach that flamed in his blood-stained belt. Behind him screamed the hordes of Ciaran, hungering for that magic jewel—ahead lay the dread abode of the Ice Creatures—at his side stalked the whispering spectre of Ban Cruach, urging him on to a battle Stark knew he must lose!