Vermeil

Vermeil or vermeille (pronounced either ver meel' or ver may') is a layer of gold plated over sterling silver.    Gold plate adheres OK, but not perfectly to silver.    Where the plating has not bonded, the silver will tarnish underneath the plating.   On the gold-plated surface, this will appear as dark, blotchy spots.   The gold-plate will darken over time, and will eventually wear off.   On large, smooth surfaces, this might be problematic.   On highly decorated surfaces, like on bali beads, the irregular darkening adds an antique effect to the piece.   If you are mixing vermeil and gold-filled pieces together, remember that the vermeil will darken, but the gold-filled will not.

Also of interest:

Bali Gold-Plated Sterling Silver Beads and Findings

Clasps

Findings