Only a few specimens of this unicorn amulet-type seal have been found. One was during Marshall's excavations at Mohenjo-daro in the 1920s (top), another at Dholavira a few years ago (bottom). It appears to have been worn around the neck, and have had room for something to be put inside.
Although Marshall himself did not favor the amulet theory, he wrote of one of these seals: "The amulet theory finds some support, however, in the shape of ... [a] seal [which] measures 0.77 in. square and 0.3 in. thick, excluding its boss. The interior has been carefully hollowed out to form a compartment measuring 0.65 in. square by 0.1 in. deep. This little chamber was formerly closed by a sliding cover that fitted into grooves closed fitted into grooves cut into two sides of the seal. Practically all the face of the seal is missing, but enough remains to show that the animal represented on it was the unicorn and that there was the usual line of inscription above it ... Owing to its necessarily small size, the compartment would be of little use except to hold a sacred object. This may have been an inscribed copper tablet, similar to the many found at Mohenjo-daro, or an inscription written on some material such as bark or leather, which could conveniently be folded up small. This type of seal would, like the Egyptian scarab, serve the dual purpose of amulet and seal." (Marshall, Mohenjo-daro, p. 382-3).