WILL IT TARNISH?
Yep. Copper does tarnish. It reacts with chemicals in the air, mainly sulfur and forms a patina. Some people love their copper patinaed, there can be a lovely array of blues, purples, bronze and gold tones in tarnished copper.
Copper is amazingly easy to keep shiny and new-looking though:
When you take off your piece, place it in a zip-locked plastic bag or tarnish cloth.
Tiny spots on flat parts of a piece can be removed by rubbing gently with a pencil eraser(yes, this works, try it on a penny!).
Or call in the big guns: squeeze the juice of a lime into a pan of water and soak your piece until you can see it shine again. No rubbing required though you may have to watch for pieces of lime pulp.