Mantle Stone of Vhyridaan

This small gem resembles an ioun stone in most respects. It floats in a loose orbit 1d3 feet from its user's head and can be separated from its owner only by snatching or netting it. The mantle stone of Vhyridaan has AC 26, 10 hit points, and a hardness of 3. Three times per day, the user may speak a command word to gain protection from spells. This effect functions like the spell turning spell, except that a mantle stone always absorbs five spell levels before being discharged rather than the usual 1d4+6.
Additionally, the owner of the mantle stone may imbue it with up to three spell levels each day, as if it were a vibrant purple ioun stone.
Strong abjuration; CL 13th; Craft Wondrous Item, imbue with spell ability, spell turning, Quicken Spell; Price 232,360 gp.
Source: Player's Guide to Faerûn