Tennis necklace, sterling silver

It looks like what it is: a real gem, cut and set the way a diamond would be. At an ordinary distance it reads as a bright, clear stone. Up close and in direct light, moissanite throws more rainbow fire than diamond, and a trained eye can sometimes tell the two apart. It does not cloud or yellow with age, which is what gives cheaper stones away. More about the stone.

Over time, yes. Gold and rhodium finishes are a thin layer over 925 sterling silver, and skin, water and lotion wear any plating down gradually. How long it lasts depends on how often the piece is worn and how it is looked after. The stone itself does not wear, and it is covered by our lifetime stone guarantee.

Put it on last and take it off first: after lotion, perfume and hairspray, and before swimming, showering, the gym and sleep. Clean the stone with warm water, mild soap and a soft brush, then let it dry. Store the piece on its own so harder jewelry cannot scratch it.

Millimetres are the stone's actual measurement across the top. Carat is its weight. Moissanite is about 10% lighter than diamond, so we also give the diamond equivalent weight (DEW): the carat size a diamond of the same measurement would be. A 6.5 mm round stone sits on the hand like a one-carat diamond. When comparing pieces, go by millimetres.

Use the size guide beside the size options to measure at home. If it is not right, you have thirty days from delivery to return it unworn, and we send a prepaid return label. To exchange, return the piece and place a new order in the size you need. The full terms are in our returns policy.