Discover our new boutique in Marseille at 42 Rue Paradis!
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My selection

Advice

ADVICE — Bien choisir, bien porter, bien transmettre — Nos réponses aux questions que l’on nous pose le plus souvent en boutique :
choisir une pierre, trouver sa taille, entretenir un bijou ou réussir un cadeau.

Our answers to the questions we are asked most often in boutique:
choosing a stone, finding your size, caring for a jewel or getting a gift just right.

The stone

The language of diamonds: the 4Cs

Two diamonds of the same size can differ considerably in value. The 4Cs – carat, colour, clarity (pureté in French), cut – form the international standard for comparing diamonds objectively, and making an informed choice.

Carat
Weight, not apparent size: 1 carat = 0.20 gram. A well-cut 0.70 ct diamond can look larger than a 0.90 ct.
Colour
Graded from D (colourless) to Z (slightly tinted). Between F and H, an untrained eye perceives virtually no difference.
Clarity (Pureté)
Internal inclusions, examined under a ×10 loupe: from IF (free of inclusions) to SI, they remain invisible to the naked eye.
Cut
The only quality shaped by the hand. It is the cut that brings the light: always favour an excellent or very good cut.

Our solitaires of 0.30 ct and above come with an independent gemmological certificate (GIA, HRD or IGI), handed over with the presentation box.

A solitaire between the jeweller’s fingers, being polished in the workshop

The right fit

Finding your ring size

The French size corresponds to the inner circumference of the band, in millimetres. The most reliable method is still to have it measured in boutique, free of charge and without an appointment – but here are a few simple guidelines to give you an idea.

  • 48Ø 15.3 mmslender fingers
  • 52Ø 16.6 mmthe most common
  • 56Ø 17.8 mm
  • 60Ø 19.1 mm

Tip: lay a ring that fits you well flat on a ruler, measure its inner diameter in millimetres, then multiply by 3.14 to find your French size. If you are unsure between two sizes, choose the larger one — an adjustment is always possible afterwards.

Every day

Wearing and caring for your jewellery

What to avoid
Remove your rings before sport, swimming, gardening and the washing-up: chlorine tarnishes alloys, and knocks can shift the settings.
The weekly ritual
Lukewarm water, a drop of mild soap, a ten-minute soak, then a soft brush behind the stone. Dry with a lint-free cloth.
Storage
Each piece in its presentation box, apart from the others: stored together, diamonds scratch gold and fine stones.
Perfume first
Lotions, perfumes and hair products go on before your jewellery: some of their ingredients dull the surface of gold and fine stones.
The annual check-up
Once a year, we check settings and clasps free of charge in boutique. It is the best way to avoid losing a stone.
Yellow gold and diamond ring and bracelet, worn

The art of giving

Giving jewellery with confidence

First, observe what the person already wears: yellow or white gold, discreet or bold, delicate or graphic. The right jewel extends a style rather than contradicting it.

For the size, discreetly borrow a ring they already own, or rely on a chain that we will measure together. And if any doubt remains, a solitaire or a plain court ring can very easily be resized or exchanged afterwards in boutique.

Every Romain Herzo piece leaves in its signature presentation box, with its jewellery card and, if you wish, a handwritten note prepared during your visit, at no extra charge.

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