Can I get a custom ring with a hidden halo?

Yes, you can. I've made about two dozen of them just this year.

A hidden halo is exactly what it sounds like - a ring of small diamonds set beneath the center stone, usually in a way that's invisible from the top-down view. You only see it from an angle, or when the ring tilts on the hand. It catches light that way. The center stone appears to float above a secret ring of sparkle.

How it actually works

The hidden halo sits on a separate cradle below the main stone's girdle. The center stone is set into a basket or a peg head, and the hidden halo is soldered to the shank just underneath it. The diamonds in the halo are usually quite small - 1.2mm to 1.8mm rounds, generally - set in a micro-pavé pattern. From straight above, you don't see them. From three-quarters view, you get a glint.

The effect works best with a center stone that's elevated enough. A cathedral setting gives you room. A low-profile basket won't. That's the first thing I check when a client asks for this: how much vertical space do we have to work with?

What it costs

About $400 to $900 on top of the base setting, depending on the diamond size and how many you're using. A full-circle hidden halo (twelve to sixteen stones) runs more than a half-circle (six to eight). The labor is in the setting - those little stones are hard to reach once the center is in place, so the setter works blind on part of it. I pay my setter about $35 per stone for this kind of work.

Where it goes wrong

Three things, in my experience:

• Not enough clearance. If the center stone sits too low, the hidden halo stones rub against the center stone's pavilion. That's a recipe for chipped diamonds. You need at least 1.5mm of clearance, ideally 2mm.
• Too much metal. Some CAD designers build the hidden halo cradle too thick. You end up with a visible metal ring under the stone, which defeats the purpose. I prefer a hand-fabricated basket for this reason - I can file the gallery rail down to about 0.8mm.
• The wrong shank width. A hidden halo needs a shank wide enough to support it visually - at least 2.2mm, preferably 2.5mm. Otherwise the ring looks top-heavy. It is top-heavy.

Who should get one

Clients who want the antique look without going full Old European. A hidden halo with a modern round brilliant center stone is a common combination - it gives you period detail with modern fire. It also works beautifully with an oval or a cushion. I set one last month for a client named Priya: a 1.6 carat oval, G/VS1, with a full-circle hidden halo in 18k yellow. The band was 2.4mm flat-profile. Looked clean from above, sparkled from the side. She teared up when she saw it.

The honest trade-off

Your ring will be harder to resize, and your center stone will sit higher than a flush setting. If you're hard on your hands - if you work with tools, or you lift, or you're the kind of person who forgets to take rings off - a hidden halo is not the move. The extra height catches on things. I've re-set two hidden-halo centers that got knocked loose by gym equipment. Both were fine because the owner noticed the wiggle before the stone dropped, but it's worth knowing going in.

A hidden halo is a detail. It's not the whole ring. The best ones are the ones you barely notice at first.