Stone of alarm
(Dungeon Master's Guide v.3.5, page 267)
Price (Item Level): 2,700 gp (7th)
Body Slot: —
Caster Level: 3th
Aura: Faint; (DC 16) abjuration
Activation: Standard (command)
Weight: 2 lb.
This stone cube, when given the command word, affixes itself to any object. If that object is touched thereafter by anyone who does not first speak that same command word, the stone emits a piercing screech for 1 hour that can be heard up to a quarter-mile away (assuming no intervening barriers).
Prerequisites: Craft Wondrous Item, alarm.
Cost to Create: 1,000 gp (plus 700 gp for base item), 80 XP, 2 days.