David and Rock, perhaps you could ask Kevin Ward if he would be willing to share his photo of a spectacular crystalized Chimney Rock Quarry, NJ specimen with this article. It is a very good photo of a major copper specimen. Steve.
Steven, The author of the Copper article is David Von Bargen and I think that I should probably not get involved at this point, but Dave is a reasonable guy and I bet if you asked Kevin, he would likely upload the image to the mindat gallery for use.
Paul, I think it may be more of a difference about the definition of halfbreed. Personally, I think of them as the "nuggets" with more than about 25% silver for a "classic" halfbreed. Specimens from the underground I would classify as a silver and copper specimen, not a halfbreed. I think that classifying a copper specimen with a spec of silver on it as a halfbreed is just marketing hype.
Silver is later in the paragenetic sequence as evidenced by the short range of diffusion of elements where the two metals are in contact.