I suppose I could list all the Artifacts I shat out during that Dawn of Worlds forum game in 2013-14. But their mechanical effect in the original context was "+1 to a thing done on the scale of divine intervention" so it's story ideas rather than mechanics.
A lot of these are just "musical instrument that does a thing" I must warn you.
The Ocarina of Fire, whoever plays it can control fire while playing it, which later became a much more significant artifact when it passed through the Void and got mutated by Void-powers
The Dancer's Bells, literal bells meant to be attached to wrist and ankle bands, which mentally compel any person who hears them to dance to the beat
The Horn of Winter, another boring one here, a horn as in the musical instrument which shoots blasts of cold when played
The Fan of Gales, similarly in the boring category, a fan which blows
a gale instead of the naturally likely amount of air movement when swung
The Earthquake Drum, which is not something you want to play in populated areas
The Living City, a living member of a race of tentacle monsters grown so large that by hollowing them out the builders could make a habitable location. The construction was performed somewhere with different laws of physics, so the poor bastard was covered in tattoos that magically enforced the subtly different physics required to not just collapse under its own weight.
The Dream Twister, a glass armonica which causes a target city to have horrific nightmares that prevent sleep. (Name totally stolen from Alpha Centauri)
The Rings of Telepathy, a weird scheme in which a whole bunch of cheap mass-producible rings were seeded into the population, and then anyone wearing one of the eight Master Rings could read the thoughts of anyone wearing one of the many, many, many Lesser Rings. So a more shit version of the One Ring when I put it that way, but with wider coverage. (There were eight master rings because the species what made them had eight tentacles and thus its number system was based on eights.)
The Book of Death, OK this one gets a description
On first reading, the Book of Death appears to be a picture book - only, the pictures are all scenes of death, some brutally quick, some agonisingly slow, all horrifying in their way. A person who looked more closely, and could decipher the musical staves in which Singer-speech of old was written, would realise that these pictures were in fact drawn in runes, runes which instructed the reader in a spell which would inflict the form of horrifying death portrayed.
And an honourable mention to
The Garden of Pestilence, which wasn't really portable, being just a collection of a shitload of poisonous plants.