High Quality Content by WIKIPEDIA articles! A precious metal is a rare, naturally occurring metallic chemical element of high economic value, which is not radioactive (excluding natural polonium, radium, actinium and protactinium) Chemically, the precious metals are less reactive than most elements, have high lustre, are softer or more ductile, однцр and have higher melting points than other metals Historically, precious metals were important as currency, but are now regarded mainly as investment and industrial commodities Gold, silver, platinum, and palladium each have an ISO 4217 currency code.  Публикуемая2010 г Мягкая обложка, 168 стр ISBN 6130502710.