What metals are used in costume jewelry?

Requirements for each question: 1-2 URL links 110 words minimum about topic. There is a total of 8 questions, the first five is due on Friday the 5th. I will add the other 2 questions after the first 5 are done. What metals are used in costume jewelry? How are they made to simulate the gold and silver they mimic? What are isomers? How are resonance structures different from isomers Compare types of isomers. Identify complex ions and common ligands. Apply the valence bond theory. Like most others, I love jewelry and come into contact with it daily. In the case of rose gold, copper is the solute and gold is a solvent (copper gives gold a slight rose colored tint). In white gold, nickel and palladium are solutes and gold is a solvent (thus the solution takes on a silvery color). Nickel is the stuff most normally associated with allergies. Contact dermatitis to nickel is not something one normally likes to have. Class: Could gold and silver also react with sensitive skin? Why or why not?