Gold is naturally yellow, but for white gold it is treated with rhodium. Rhodium is a coating that gives it its white color and shine. Sometimes rhodium can wear off of a ring and you will see a...
The mineral "rutile" is titanium dioxide, which can have a "gold" color. Other elements within rutile include iron, tantalum, and niobium.
Actual gold strands trapped within quartz crystals do exist,...