SRD:Periapt of Wisdom

Periapt of Wisdom: Although it appears to be a normal pearl on a light chain, a periapt of wisdom actually increases the possessor’s Wisdom score in the form of an enhancement bonus of +2, +4, or +6 (depending on the individual item).

Moderate transmutation; CL 8th; Craft Wondrous Item, owl’s wisdom; Price 4,000 gp (+2), 16,000 gp (+4), 36,000 gp (+6).