Contemporary Jewellery - Costume jewellery should be taken care of. Many embellishments on costume jewellery are only secured with glue rather than set into the piece. Costume jewellery should never be immersed or make contact with harsh chemicals. Wiping it down with a damp, warm cloth and then drying it with another cloth is the best care for it. This keeps dirt from building up and making your jewellery look dull.