Should I avoid certain diamond shapes if she works with her hands?

Yes. Two shapes, and I’ll name them in a minute. But the real answer isn’t just about shape - it’s about the life the ring is going to live, and whether anyone has been honest with her about what a diamond can survive. I see chipped points walk through my door about once a month, and the conversation usually starts the same way: “I just bumped it against the counter.” The counter won.

Marquise and pear cuts are the worst offenders for a hand that works. Any shape with a sharp tip concentrates stress into a tiny area, and diamonds have cleavage planes - hit one at the wrong angle and a sliver comes off clean. A marquise’s points are acute, sometimes around 45 degrees, and even with V-tip prongs (which I use on both ends, always) you’re trusting a few millimeters of gold to absorb a blow. It usually does, until it doesn’t. Princess cuts are a close third because the corners sit just barely protected by the prongs, and I’ve re-polished enough chipped princess corners to know they’re fragile in exactly the wrong way for someone who opens boxes, handles files, or scrubs in for surgery.

Heart shapes, trillions, and sharp-cornered emerald cuts belong in the same category, though a deep channel or full bezel can shift the math. I’ll set any of these - I built a pear for a chef named Chloe two years ago, and we both knew the risk. She was back in eight months with a 0.6mm chip at the tip. We reset the stone into a pendant and made her an 18k yellow gold solitaire with a 1.2 carat round brilliant, six-prong head, set low so the girdle barely cleared her finger. That ring hasn’t moved since.

The safest shape, period, is the round brilliant. No corners, no points, and the pavilion angles on a well-cut round spread force evenly. Ovals are decent if the culet is protected - the rounded ends don’t catch the way a marquise tip does, though I still prefer a six-prong setting to keep the stone stable. Cushion cuts with rounded corners, old European cuts (which are basically soft-edged rounds), and rose cuts that sit flush all reduce the risk. But shape alone isn’t the whole game.

The setting matters at least as much as the shape. A tall peg-head mounting that elevates the stone an eighth of an inch above the band is going to snag on nitrile gloves, gym equipment, hair, all of it. I’ve built rings for nurses, potters, and a marine biologist who spent half her day elbow-deep in tanks - and for them the answer was always a bezel. A full bezel wraps the stone’s girdle in metal, and it eliminates the prong-snag problem entirely. You lose a little light return (about 10-15% depending on how the bezel is cut), but you gain a ring that can take a beating. For someone who works with her hands every day, that’s the trade I’d make every time.

If she wants a marquise and she’s a physical therapist, I’ll build it. I’ll use heavy V-tips, I’ll set it as low as the culet allows, and I’ll include a care note that says “don’t wear this to work.” Then I’ll suggest a plain 2.5mm comfort-fit band in 14k white gold for the workday. Most of my couples end up doing that anyway, regardless of shape - the engagement ring stays home, and the hand gets a practical symbol that doesn’t need a repair ticket six months later.

A diamond isn’t indestructible. The trade likes to sell it that way, but anyone who’s spent a Tuesday morning with a loupe and a chipped girdle knows better. The shape you pick is a question of how much risk you’re willing to manage. For a hand that works, I’d manage it with a round stone in a low bezel, and I wouldn’t lose sleep.