Metalmist Sphere (Lesser)

This sphere contains small fragments of thunderstones within a colloidal suspension of a precious metal. When you twist the sphere, it creates an opaque mist in a burst centered on one corner of your space. Creatures within that area are concealed, and all other creatures are concealed to them. Any creature with a weakness to the precious metal that starts its turn in the mist takes damage equal to its weakness. The mist lasts for 1 minute or until dispersed by a strong wind. Most metalmist spheres are filled with silver or cold iron, but more expensive versions containing other ingredients might exist.

The radius of the burst is 5 feet.