Medallion of the First Engineer

This heavy bronze medallion is the size of a clenched thumb, suspended from a chain of interlocking steel links. Its face bears the profile of a forgotten engineer crowned with a ring of tiny gears, while a sliver of emerald crystal pulses beneath the engraved surface. When held near a mechanism, the medallion grows warm and emits the faint scent of hot metal, rain-wet stone, and cedar oil.