Silver/Gold Tone Jewellery
Silver and gold tone jewellery should be kept away from water, perfumes or any other liquids to keep them from tarnishing.
Silver Plated Jewellery
Sterling silver plated jewellery will last longer than silver/gold tone jewellery. However, to keep your item(s) in the best condition, they should still be kept away from any liquids. 
Sterling Silver
Sterling silver jewellery will last the longest but can still tarnish when exposed to air over a long period of time. Store jewellery in an airtight container to prevent this from happening. Use a polishing cloth to clean and keep it in the best condition