Gold became "gold" not because it was "useful" -- but almost precisely because it "wasn't." It was shiny, pretty, and scarce, and also NOT GOOD for tools. Its rise as a symbolic store of value is likely directly attributable to its lack of intrinsic value.

But nobody used iron pyrite for jewelry, much, because it's neither malleable nor ductile -- properties which make gold useful for wire and leaf, and later turn out to be important for electronics, too.