Polished stuff is tricky, you need to light the reflections, not the object.
there is some stuff on this over at strobist,
one bit about lighting a hard drive, and others about lighting cutlery and glasses
A "light tent" is the easiest way to do it, and you can easily make your own, otherwise you need to bounce light off the ceiling and walls in a nice white room - the toilet typically works well, close the lid, put down the object, aim flash/other light source at the ceiling and snap away
EDIT - just saw you are trying to use your iPhone - that makes it a little trickier, though the principle is the same.
Either a light tent outside, or your brightest light inside and bounced off the ceiling, an assistant may be helpful to hold/aim the light