Shuddering fossil is a special type of currency applicable to add speed modifiers but has no influence with mana modifiers. It multiplies the weight of modifiers with speed tag by 10 and mana tag by 0. With this one of fossils minions have up to 6% increased Attack Speed and Cast Speed. In the Path of Exile game the drop location for the item is Azurite mine, namely Frozen Hollow. One can buy POE Shuddering fossil form Niko the Mad for 10,000 Azurite or exchange for 5 Chaos Orbs with other players.