•which boundary is mineral rich (gold, silver)?

Convergent plate boundary is rich in gold and silver.

Explanation:

There are three types of plate boundary such as Convergence, Divergence and Transform plate boundary. Most metallic minerals found in convergence plate boundary. Gold and silver are deposited in both convergent and divergent margins but rich in Convergent plate margin. Precious metals such as plutonium, gold, silver, etc. are mostly found in convergence of two plates. Convergence occurred in three ways such as Continent–Continent, Ocean–Ocean, Continent–Ocean.