What is the diffrence?
Well to be named Sterling Silver any item must reach at least .925 percent pure with only 7.5 parts of another metal, This other metal is usually copper to ensure hardness.
White Metal or Tibetan Silver:
White metal is a term by jewerlers given to a alloy of tin and antimony. It is a silver tone in its colour and in tin plate.
As you will observe the diffrences can have an effect on these that are elergy to metals other then silver.
You should always ask your seller if the item you consider buying, especially in tibetan bracelets is either sterling .925 or white metal. If the item is sterling silver it will have a small .925 stamped on the item. This is true for all sterling items comming from Nepal.