High yield gold trimmings?

I've seen several mentions of people saving the gold contacts from printers, ink cartridges, etc. Here is some gold contacts on various ink cartridges:



What about the contacts on cell phone batteries......does anyone mess with these? Do they yeild enough to remove?



Here are a couple trimmings from some older batteries:






Has anyone had any of these contacts refined? I'm starting to accumulate and am curious to the value. Are these considered high yeild or am I wasting my time? Adam