What should I do if a tiny diamond falls out of my halo setting?

First, take the ring off and stop wearing it. A missing halo stone is not a wait-and-see situation. The little stones around a center stone share prongs, and when one falls out, the prongs holding its neighbors have already shifted or worn thin. You'll lose more.

If you found the stone, put it in a small zip-top bag, not a tissue or your pocket. I've had clients hand me a crushed tissue with a 1.4mm diamond inside, and somehow they're surprised when it's gone. Write the date and the word "ring" on a piece of paper and put it in the bag too. Your jeweler may be able to reset the original if it's not chipped or abraded.

Do not glue it back. I don't care what the internet says. Cyanoacrylate cures into a brittle film that's harder to remove from the prongs and the stone than just paying for a proper repair. It also doesn't hold under daily wear, so you'll be back in two weeks, and now the mess is worse.

What to do right now

Call your jeweler and tell them two things: the stone fell out, and whether you have it. If you don't have it, say so. No shame. I'd estimate 60 or 70 percent of lost halo stones come in without the stone, and the replacement cost is often less than the deductible on a jewelry policy.

If the ring is insured, call your insurer or agent first, because some policies want a photo of the gap before any repair work starts. Then take it in.

At the bench I'll check every prong in the halo under magnification, not just the empty seat. Halo stones fail in groups. A client named Nicole came in last March with one missing melee, and by the time I inspected it she had three more loose enough to move with a needle. We ended up retipping seven prongs and replacing two stones, not just the one that fell. The repair ran about $230, which she wasn't thrilled about, but the alternative was losing a center diamond if the whole basket let go.

Replacing a missing 1.3 to 1.6mm melee diamond in a halo typically costs between $35 and $120 depending on the stone quality and how much prong work is needed. Retipping is separate, usually $25 to $45 per prong. If the halo has French-cut pavé or fishtail pavé, the cost can climb because the setter has to carve the metal back to hold the tiny stones properly, not just press a prong over again.

What not to do

Don't keep wearing it. Don't clean it in an ultrasonic, don't steam it, don't wear it to the gym or while gardening. Loose stones rattle free with vibration and impact. And don't do a DIY tightening job with a pair of tweezers from a drugstore repair kit. You'll crush the prong or scratch the stone, and I'll have to fix that too.

Halo settings have a weak spot, and it's not a secret to anyone who sets them for a living. The more stones you put around a center, the more points of failure you create. When I build a halo now I'd rather use a shared prong or a micro-pavé approach with a heavier outer rim, but plenty of older halos were set with thin prongs and no gallery wall to protect them. If yours is one of those, your jeweler should talk to you about whether the whole top needs rebuilding rather than chasing one stone at a time.

Bring the ring in. The repair is small, but ignoring it isn't.