Will a graphics card break if there is a tiny dent in one of the little metal pieces? I just checked my unused graphics card today, and found one... Currently, I'm unable to test it since I am ordering a new PSU to power it.
If you are talking about what I think you are talking about, you are fine. The Copper or Zinc in the heatpipes are typically imperfect with blemishes, but the heatpipes are there to transfer heat, and do not affect your card's performance at all.
If you are feeling uneasy about it, send it back. Most websites will gladly accept it back and send you a new one!
Huh. Well I'm not an expert on the actual PCB but if I were you I'd just send it in to be safe. There's no point in keeping in when it may have issues down the road, especially when many websites will honor an RMA without much trouble.