My jewelry is always created with genuine crystals - most are raw, some are tumbled or polished.
I recommend removing your crystal jewelry before bathing and before going to sleep.
Copper is considered a conductor of energy and is said to intensify, enhance and channel the properties of the crystal it is being used with. Copper will oxidize and the color will change - much like a new penny as opposed to an older one.
Sterling Silver, much like copper, is also said to strengthen the effects of the crystal. Sterling Silver will tarnish with time and can be polished using a silver polishing cloth. Never immerse your crystals in silver cleaning liquid.