In an ideal world, the provenance of every piece of art and religious object would be known.

Who created it, who owned it, who sold it and who bought it -- a transparent record would seem especially useful in a field where documented authenticity can only enhance value.

But for some collectors who simply want to own an object, not display it publicly, transparency is the last thing they want.

Such is the case with the 70 objects the Hopi Tribe and others consider sacred that are scheduled to be auctioned in Paris Friday.

Neither the collector who is selling the objects nor the auction house has volunteered any provenance.

That might be because Hopi leaders consider them "stolen" -- sacred objects belong to the Hopi people, they say, and can have no other owner, even if a tribal member sold them or gave them away.