Mpfffff..... Some clarification required.

FINE silver plating (most of it) *will not* tarnish from exposure to air, nor will it form sulphur compounds - without other contributing factors. Sterling silver (.925 silver) is an entirely different matter.

What is going on here electro-galvanic (galvanic action) *corrosion* of the copper plating under the silver - and most things electro-silver-plated other than brass are first copper-plated to guarantee proper adhesion.

The black material noted is CuO, not tarnished silver.

Peter Wieck
Melrose Park, PA