Instruct: Classify a given review as either positive or negative.
Query: keeps tarnishing

Necklace and chain were super shiny at first but after 1st month the chain began to tarnish. Cleaned it w/ silver polish and black kept coming off. Would look just o.k. and then 2 days later it would turn black and leave marks on my neck. Don't think the chain is sterling silver after all.I am happy with the pendant but not the chain.