Does anyone like arabic food.and what is your favorite cuisine???
TarnX works the best for meThen, store your case in a place that minimizes air flow around itIf you have a zipper compartment in your purse, that would be goodPollution and oxidation are what tarnish your silver, in addition to the moisture the other poster mentioned.
If it is real silver, use silver polishCleaning aisle at Lowes, Walmart, Home Depot, etcAny other substance can tarnish your case.
If its true silver and not plated use tooth paste IDK why but it works great.