Gold is a well known and quite rare precious metal that has been used as a payment method and storage of wealth for millennia. It's a soft metal used in jewelry (50%), investments (40%) and industry (10%). It's consistent available supply and various use cases make it a wanted and expensive material.
Gold as an investment
Gold has proven to be a hedge against the monetary system in troubling times like economic recessions and high inflation. In these situations gold usually holds it's value. It can also be a interesting long term storage of value regardless of the state of the economy.