Shadows for Silence silver

So i just started Shadows for Silence in the Forests of Hell, and there is a big emphasis on people using silver. For example, silver crossbow bolts, people line rooms in silver, etc.. silver has never really been an important metal in the Cosmere. So I’m wondering is the silver on this planet actually aluminum and all the people just call it silver? Apparently the silver crossbow bolts can kill cognitive shadows and I’ve never heard of silver having properties like that. Not to mention the rooms lined in aluminum later in the Stormlight series being just like how people use silver in this story.