The precious metals are those few that are not gasses, and not reactive. Of these, only gold (Au) and silver (Ag) are not extremely rare and hard to extract and work.
A while back, I posted a radio article by Planet Money on why gold is so valuable, and has been used for money for so long (God, Glory and GOLD: but why gold?). They’ve now created a nice video explaining the same thing. Though there’s less detail, the dramatic visuals (of the reactivity of sodium for example) make it quite interesting.