valuing gold - the value of gold

valuing gold - the value of gold: which is worth more, a kilogram of stone or a kilogram of gold? the question about its value probably seems ridiculous but only to the merchant.  the artist will always answer "all materials are equally valuable as I am concerned". 
Venus de Milo would be equally precious, whether made of common stone or gold... 
in Paros Greece the streets are paved with marble - in Wall Street with stone