These rare, highly prized devices are fist-sized green stones made
by some forgotten magical means. They glow when operating, and
are brittle. When worn next to the skin they confer upon the wearer
the protection (spell immunities) of a Mind Blank spell, as well as
immunity to: Chaos, Forget, Geas, Hold Person, Hypnotism (but
not Hypnotic Pattern or Fire Charm), Mass Charm, Quest, Score,
and Sleep. The wearer also gains +4 on saving throws against
Fumble, Ray of Enfeeblement, and Trip, and is allowed a saving
throw against both Otto’s Irresistible Dance and Maze spells (if
made, the durations of effect are halved, rounding up).

These amulets may be worn by any class of character. The
protection they give is involuntary (i.e. the wearer cannot communicate
telepathically even if he or she so desires). Protection only
extends to 11-44 (1d4) spell levels before the amulet is exhausted.
(For this purpose, protection against a psionic power drains the
levels of the equivalent spell.) Note that the amulet only counters
spells listed, and is in no way affected by other spells (for instance
Lightning Bolt). Exhaustion will be mentally evident to wearer, and
visually evident to others; the amulet will blaze brightly for 4 segments
before slowly fading to darkness.

The amulet will recharge at the rate of 1 spell level/turn but will
not counter spells which it lacks sufficient power to negate—that is, it
does not give partial protection.

X.P. value: 5,000; G.P. value: 30,000.