Your sitation (hundreds upon hundreds of aluminum to any gold rings, or NONE in your case) is what makes me chuckle when I read the following admonition on a forum, as the "secret recipe" for finding gold rings:
"If you want to find gold rings, just lower your discrimination, and dig all the foil and tabs"
Doh! As if that were the "recipe" or "solution" finding gold. Then the poor newbie goes out into the blighted junky parks, digs just till his arms fall off, and asks "what am I doing wrong?" Then sure enough: someone comes back on AGAIN, and tells the poor newbie "just dig enough junk, and you'll be sure to eventually find gold rings". And then sure, one day, perhaps he DOES find a gold ring. But if he has any brains at all, he wises up and realized, it's just not worth it to strip-mine junky parks like this.
This "dig all" recipe is silly on a few fronts: For starters, it's already a GIVEN that gold rings are low conductors, like foil and tabs. Who ever disputed that? That's already a given premise. The REAL ISSUE is, not just simply digging all, but WHERE you hunt. Because let's face it: there's junky blighted urban inner-city ghetto parks where you will certainly dig 1000 pieces of cr*p before you EVER dig a gold ring. So therefore, the BIGGER part of the recipe, is where you hunt.
And the best location, and best ratios for junk to gold, is swimming beaches. There are also certain types of park usages that also lend themselves to better jewelry ratios: sand volley-ball courts, some athletic applications where there is NOT picnic type usage of the turf (picnics, eating, drinking, and BBQ cooking lend themselves to nasty junk ratios).
