Silver tarnishes.  Its just a fact of owning it!  However, there is a really easy, safe and fast way to clean it - whether its jewelry with tender semi-precious stones, or large trays and platters with intricate designs. 

Line a large PLASTIC container (one that will hold the items you wish to clean spread out) with 7 layers of aluminum foil, shiny side up.  Poke several fork holes in the foil - five or 6.  Place the items to be cleaned on the foil, not touching each other, with as much contact with the foil as possible.  Heat water to just below boiling, then pour over silver.  Quickly sprinkle some baking soda over the item, and it will magically shine!  Remove, rinse and rub with a soft cloth.  It should be bright and sparkley!  If the tarnish is really bad, do it again, until it is cleaned.  You should smell a rotten eggs sulphur smell - that is normal!