In Colorado, I am always on the lookout for chalcopyrite - it is a very heavy rock for its size, and often has a yellowish/orangeish metallic look to it in places. Pyrites that are very cubic in shape tend to be less interesting than pyrites that have few (if any) sharp edges. If there is gold in the sample, its most likely in the rusty areas on your sample. Regular copper veins tend to look green - there are many copper/gold veins (Quartz has little to do with this type of lode area) - usually far more copper than gold in any sample.
Borrowed from another Website:
Gold is classified as a "chalcophile", which means that gold has an affinity for sulphur. However, there are no known combinations with sulphur, but several with elements that are related to sulphur, such as tellurium, (known as telluride) and selenium. Because of this relationship with sulphur, you will find gold associated with chalcopyrite, which is a combination of iron pyrite and copper. Since Gold loves copper so much, all of these elements are often found together in varying amounts.