Jewellery bought to be worn constantly fails in specific, predictable ways. Knowing them before you buy is the whole of the advice.

Chains: structure beats weight

Rope and box chains hold their shape and rarely knot. Fine curb and snake chains look wonderful and tangle in a pocket. Singapore chains are the worst offenders — beautiful movement, and a knot that needs a needle and patience.

• Rope: the most forgiving for daily wear. Hides scratches well.
• Box: clean and modern, but a single crushed link is a visible repair.
• Cable: simple, repairable link by link, and easy for any jeweller to shorten.

Clasps are where chains are actually lost

Spring rings are inexpensive and wear out — the spring weakens, and the chain comes off without you noticing. Lobster clasps are stronger and open more easily with one hand. For anything of real value, ask for a lobster clasp with a safety figure-of-eight.

Why 18kt for daily wear

22kt is softer. On a piece worn daily — a band that knocks against desks and steering wheels, a chain that catches on clothing — 18kt keeps its edges and its polish considerably longer. You trade a little of the warm yellow for years of wear.