Many nouns behave like adjectives:
chocolate cake, pineapple juice, orange ice cream
book cover, radio station, gas station
In some cases, nouns and adjectives have different forms:
noun adjective:
wool - woolen
wood - wooden
Some names of materials have adjectival forms which have a metaphorical meaning, for example:
gold watch – a watch made of gold
golden sunset – a sunset that looks like gold
silver coin – a coin made of silver
silvery voice – a voice that has a clear ringing sound
stone steps – steps made of stone
stony silence – an attitude that shows no friendliness