Silver Heart necklace with diamonds

How do I clean Necklace (Silver)?
Hey guys. I have a beautiful necklace my boyfriend bought me but I have removed So it becomes a little dirty. It is silver with a diamond in it. (If it helps her "Open Hearts" by Jane Seymore) I want to bring the luster money back but I do not know how clean I do not want to damage the diamond. And when you turn around the collar is empty and there is little ground, but I do not know how to clean? Thank you for your time guys! =] X
Silver Polish and cellulose sponge that is in the pot you do not do well.
Sterling Silver Heart Diamond Pendant Necklace