My sis lives in San Diego ,and knew of a spot they call shell canyon. Im sure thats copper . Did not see anything in the way of geodes ,but then again ,I really did not think to look..lol. I was too excited about all the shell and clam fossils.Granite with pyrite? Pyrite can fool you often hence the name fool's gold.
Since you were in Ocotillo, did you pick up any geodes? You were very close to tourmaline country, about 30miles into the mountains.
Copper will oxidize green, even copper ores that haven't been exposed to air or water will be green, probably a pyrite, zinc, or lead all retain that metallic luster long after exposure to elements