Iron is a base metal and is not as stable as gold, silver or stainless steel. When it comes into contact with oxygen in the air or water, it will try to combine with the oxygen to create an iron oxide. We know this as rust. This is the reason why you seldom see iron in its naked state. Iron is protected in various ways: paints, glazes, varnishes, oils and waxes. Your jewellery piece has had a quality clear varnish applied to help protect it.
Your jewellery loves to be worn often. The oils in your skin help to condition the metal much like when you season a cast iron skillet (typically rinse, dry and apply an oil then heat it briefly - no soap as that is corrosive). Your iron jewellery can be treated similarly. Keep it dry and rub a little oil occasionally if it was exposed to water.
If it does get wet with substances like soaps & detergents, chlorine or salt water, rinse it with clean water and dry thoroughly using a hair dryer or leave it in the sun briefly. Apply some oil, you can use coconut oil, olive oil, or any other oil safe for cooking. Rub it on and buff it off.
Some people like to hang and display their jewellery. That would be great...as long as you aren't doing so in a steamy bathroom. Water and humidity are its foes.
