The short answer
Box chain. If you want one chain for a pendant and do not want to think about it, order a 1.2 mm round box at 18 inches ($822) for a light pendant, or a 2 mm at 20 inches ($1,943) for a medallion or anything with real weight. It is what jewelers put pendants on, and for good reasons.
Why box chain wins
Every link on a box chain is a small square, so the chain is dense and strong for its width, it does not twist, and it does not kink. A pendant bail slides along it without catching. It has no pattern of its own, which is exactly right when something else is the focus. And because the links are closed squares, it takes weight without stretching. A 1.2 mm box weighs about 4.3 grams at 18 inches, more than a rope at the same width, and every one of those grams is doing work.
The other good choices
Wheat. Braided, dense, smooth. Holds a pendant well from 1.8 mm up and looks finer than it weighs. 1.8 mm wheat, 20 in: $993.
Curb. The strongest choice for a heavy pendant, a religious medal or a medallion. Lies flat, so the pendant sits flat against it. Go 2.4 mm or wider. 2.4 mm curb, 22 in: $1,594.
Figaro. The long link in every fourth position gives a bail a natural place to rest. 2.25 mm and up. 2.25 mm Figaro, 20 in: $902.
Rope. Works, and it is the brightest chain, but a rope has texture and a pendant bail can catch on it. Fine for a small pendant at 1.5 mm. 1.5 mm rope, 18 in: $340.
The ones to avoid
Herringbone. Never. It is a flat ribbon of gold and a pendant will crease it the first time it swings.
Paperclip. Charms clip straight onto the open links, which is charming, but a pendant with weight will find one link and hang crooked. Keep it for light charms.
Mariner. Same open-link problem at a smaller scale. Small pendants only.
Anything hollow. A pendant bail rubs the same spot on the chain every day. On a hollow chain that spot wears through. Solid vs hollow if you want the full case.
Width and length for a pendant
Width. The chain must fit through the bail with room to move, and it should be narrower than the bail is tall so the pendant hangs from the chain instead of gripping it. For a pendant under about 5 grams, 1.2 to 1.5 mm. For 5 to 15 grams, 1.8 to 2 mm. For a heavy medallion, 2.4 mm and up, in box or curb.
Length. A pendant wants to sit at or just below the collarbone. That is 18 inches on most women and 20 on most men. Go to 22 if the pendant is large and you want it on the chest. There is a full breakdown in the gold chain length guide.
All of these are on the gold chains page, solid 14K, made in the width and length you order, priced to the live gold market with insured shipping included. Start with the box chain.
