People typically think of purchasing gold in ounces, however you can also get them in smaller divisions

There are gram-card type products where it's a 'card' of gold comprised of gram sections that are breakable

Silver is more volatile than gold, but it's possible to have the best ROI with silver

Edit: Don't neglect copper. Copper is heavy, so if you don't need to be mobile it's not a bad idea. Copper is in bullets, wires, it can help with sanitizing water, and it's not too tough to work with.

People typically think of purchasing gold in ounces, however you can also get them in smaller divisions

There are gram-card type products where it's a 'card' of gold comprised of gram sections that are breakable

Silver is more volatile than gold, but it's possible to have the best ROI with silver