How do you use "Precious" to turn invisible?

[Foodstamp]

I have been trying to figure this artifact out since I bought the game. It seems to be a unique item that drops from Bogus. When I equip it on a commander it only seems to give a slight stat increase but I don't gain any option for stealth.

I've even tried using precious on hoburg thinking maybe the special effects are tied to unit slots for "hobbit" type creatures.

One last question as well concerning this item. Will some type of horror "find" my unit while I have it equipped or will horror marking occur etc?

Please let me know if you can offer any information because in my current MP game, if I cannot unlock the power of this artifact, all is probably lost and I might as well go AI.