Arcane Concealment

This ritual prevents a Medium or smaller object from being magically located (using Locate Object, for example) or summoned by anyone except the designated owner. Spell can be cast on valuable gems, coins, jewelry, art pieces, or magic items. It can also be cast on a small recipient containing a multitude of objects (such as a chest), protecting all its content at the time of the casting.

To protect the object from magic scrying sensors as well (such as Clairvoyance or Scrying spells), the 8th level spell Nondetection is required. 

Realmslore

This anti-theft ritual is normally available in large cities that have a temple to Gond, Deneir, Oghma, Mystra, Savras, or Asmodeus.