Creating a transparent background...

I have a silver object on a white background. There are a number of gaps in the silver object where the white background is visble.

I want to remove the white background surrounding the object as well as all areas where it appears in the gaps of the object.

I've been using the magic tool to try and select the white backgound but too much of the silver object itself is being detected.

Do you have any suggestions on the best way to go about this.

Thank you very much for your time.

B R