I know I am a few years late to this trend, but I did that thing that used to be huge on the internet and took a hammer to a bunch of aluminum foil and it actually worked! I thought it would be terrible, because every guide I found eventually suggested that you bring out your belt grinder and a bottle of aluminum polish, and I am not a metal worker, so I don't have that. Turns out you can get a very satisfying ball of aluminum with just the foil, a hammer, any kind of flat surface to work on and some toilet paper for polishing.
It's shiny and I made it and I can use it as a stress ball by just tossing it from one hand to the other and feeling the satisfying weight. I love it!
How heavy is the ball?
As heavy as the roll of foil it's made from, but much more compact. Around the weight of a small can of soda.