The chain on this piece is definitely sterling. The pendant could be sterling, but it isn't marked so we are 100% sure.
This piece was created by a coven of Asian witch. The type of magic that they practice doesn't necessarily have a name, but it is extremely powerful. It isn't necessarily white light, but it isn't dark either. I guess the best way to describe it would be to say that it is intention magic. It is very close to Voodoo because it uses elements of the Earth as well as elder spirits that once lived on Earth but have been elevated to higher realms.
This piece is a spell-casting locket. You will put a personal effect or a small picture of the person upon whom you wish to cast a spell. You will then meditate with the piece and allow your mind to cast the spell. The energies in this piece will turn your thought forms into the magic that can be cast upon others. You can use this piece to cast these energies upon yourself or others. You could do something in goodwill such as wealth or longevity. Conversely, you could use this piece to cast revenge upon those who have hurt you or done you wrong! This piece is powerful, but remember with power comes great responsibility!