Vein deposits of gold and silver are formed by igneous intrusion.
Along with gold and silver, they are known as precious or noble metals.
Vein deposits of precious metals are formed by igneous intrusion.
igneous intrusion causes vein deposits of what?
Options:
1) Sediment
2) diamonds
3) water
4) precious metals
5) oil
6) Calcium carbonate
7) graptolites
8) hydrogen and oxygen