Stone of WeightEquipment 2
Source Pathfinder Gamemastery Guide
Weight light
Also known as a loadstone, this small stone appears nonmagical and has a lovely sheen, giving the impression that it could be a valuable or a notable item or a magic stone of some kind. When you've carried the stone on your person for 1 minute, its curse activates: the stone's size does not change, but it suddenly increases in weight to 5 Bulk. This additional weight does not cause the stone to deal more damage if thrown or used as a weapon. It reappears in your possessions within 1 minute if you discard it, and can't be destroyed or thrown away permanently, or even placed in a container that would reduce or negate its Bulk (like a bag of holding), until it is subject to a remove curse spell or similar magic effect. Once the curse has activated for the first time, the stone fuses to you.
Traits
This rarity indicates that a rules element is very difficult to find in the game world. A rare feat, spell, item or the like is available to players only if the GM decides to include it in the game, typically through discovery during play. Creatures with this trait are rare. They typically can't be summoned. The DC of Recall Knowledge checks related to these creatures is increased by 5.
ConjurationEffects and magic items with this trait are associated with the conjuration school of magic, typically involving summoning, creation, teleportation, or moving things from place to place.
CursedAn item with this trait is cursed to cause trouble for its owner. A curse isn't detected when the item is identified, though a critical success reveals both the presence and exact nature of the curse. Cursed items can't be discarded once they've been triggered or invested the first time. The item can be removed only if the curse is removed.
MagicalSomething with the magical trait is imbued with magical energies not tied to a specific tradition of magic. A magical item radiates a magic aura infused with its dominant school of magic. Some items or effects are closely tied to a particular tradition of magic. In these cases, the item has the arcane, divine, occult, or primal trait instead of the magical trait. Any of these traits indicate that the item is magical.