Something that's golden is made out of gold. A queen in a fairy tale might wear an elaborate golden crown.
Aside from golden ornaments and jewelry, things the color of gold are also golden, like a boy's golden hair or golden fields of wheat. If you talk about a golden time or a golden opportunity, you mean something marked by luck, peace, and happiness. In Old English, it was common to add the suffix -en to mean "made of," but golden is one of just a few of these words in modern English (including wooden and waxen).