Vein deposits of gold and silver are formed by igneous intrusion, and jewelry is made of silver, gold or platinum and is usually set with precious stones. Given these facts, what geological formation must occur for the availability of material for silver jewelry to occur among the following options:
- Igneous intrusion
 - Metamorphic Layers
 - loose soil
 - tectonic plates coliding
 - Physical weathering
 - Volcanic mountains
 - permineralization
 - Sedimentary deposits


 

 Igneous intrusion        