|“||Same thing happened to Lot's wife. Iodize the poor sucker, and your kitchen is stocked for life.||”|
— Balthazar, as he describes the nature of the object
It can turn a human into a pile of salt. It can't harm or destroy angelic beings or at least archangels but it can disintegrate the vessel they're using.
Lot was forewarned by angels of the destruction of Sodom and Gomorrah to leave without looking at the city. His wife was reluctant to leave behind the life they had built there and all their possessions, and when they tardied, the angels had to physically grab the family by the hand and lead them out of Sodom so they could escape in time. As he and his family fled the destruction, his wife looked back in longing despite the angels telling them not to, and she was turned into a pillar of salt.