Diamond Necklaces

With a necklace the length decides almost everything, and it is the one measurement people guess at when buying as a gift.

Sixteen inches sits at the base of the throat — a choker length, close to the skin, and it needs a bare neckline to work. Eighteen inches falls just below the collarbone and is the length most diamond pendants are designed around; it works over almost anything. Twenty inches and beyond sits on the chest, layers well with shorter chains, and reads more casual.

The chain matters more than its price suggests. A cable or rolo chain is strong and holds a pendant square. A box chain is the least likely to kink. A rope chain is the most brilliant on its own but also the most prone to catching. Whatever the style, the gauge should be proportionate to what hangs from it: a heavy pendant on a fine chain will wear through the bail over years.

Check the clasp. A lobster clasp is more secure than a spring ring, and easier to fasten one-handed — which is how you will actually be fastening it.