The intangible artifact:
This object might as well be a semi-real manifestation of magic itself. Depending on the person "looking" at it, it can appear to be anything, but always appears to be the same thing to that person. (EG, they always see it as whatever they see it as.) The object radiates magic with unbelievable intensity, but essentially does nothing else.
As stated, the object is intangible. It has no real physical substance, and can only be seen, and "felt" (in terms of its magical aura.)
It has been hypothesized that it appears as an item the person viewing it greatly desires, but this is not entirely true. Rather, if there are any rules governing the appearance observed by somebody, only one seems to hold: It always appears as something "familiar" to the observer. (EG, it could be a pocket watch to somebody on earth, or an unusual eating utensil to somebody from another planet.) The object is always just laying around, and seems to migrate from "person to person" without rhyme or reason, as if it has a mind of its own, but the people it chooses to be seen by are always people that physically interact with each other in some way. One day, it will be there, sitting on your bed, and you will be unable to move it, touch it, or affect it in any way, but it will be there, in your place of residence, and there is nothing you can do about it. (It might not appear on your bed, it might appear in your refrigerator, or in your fish tank-- the location, and the form you perceive it as, are quite random.)
For those it has affected, it often becomes the focus for crude jokes about the inappropriateness of the perceived item, and where it is placed, (Sometimes it is perceived as a NSFW type item, for instance) or even arguments about what it actually "is." (as it appears as different objects to different people, and more than one person can "see" it at once.)
When attempts to photograph it happen, the photographs themselves take on similar mysterious properties, but are likewise "useless". (EG, a person taking the photograph of "the object", will always see the resulting photograph as being one of the object, but when shown to another random person, that person will see the object as something completely different. Such photographs do not exhibit magical auras, suggesting that this is not illusion magic, but is actually the result of the photograph accurately depicting the object.)
There is no way to tell which person exposed to the object will become its new "owner".
Attempting divination, such as "Identify item", results in the caster appearing to "zone out" for several seconds, with their mouth agape, but otherwise fails, as if the object is not real.
Attempts to psychically contact the item results in zero contact, as if the object does not exist, or has never been in contact with a mind at all. (this includes attempting to derive its psychohistory.)
The magical aura of the object cannot be used in any tangible way, but it does seem to attract magically enabled, intelligent, and curious minded people to itself like a siren song.
People affected by the object are not harmed by it in any way, excepting for being ridiculed or teased by people they know for "always leaving that thing laying around", due to its often "inappropriate" (thematically, situationally, decorum, or otherwise) appearance.