By Baptiste Murier, antique and second-hand dealer in Île-de-France.
Many families keep an antique ring in a drawer: a grandmother's engagement ring, a solitaire, a marquise ring or a "toi et moi" ring (two stones side by side). Often the diamonds do not have the bright sparkle of modern stones. That is not a flaw. It is the sign of an old cut, made by hand before the modern brilliant cut took over. So to value an antique diamond ring, you need to look at three things: the cut of the stones, the metal and its hallmarks, and then the piece as a whole.
Why does an old diamond sparkle differently?
A diamond cut today follows proportions calculated to send back as much light as possible. It gives a white brightness and very lively flashes.
Old diamonds were cut by hand, with the aim of keeping as much of the stone as possible. The result is different: a softer light, broader flashes, and reflections that change a lot with the light in the room. By candlelight or under a warm lamp, an old cut is often very beautiful.
This difference is the first clue for dating a ring. It does not tell you everything, but it points you in the right direction.
How do you recognise an old cut?
Take a loupe, ideally a jeweller's loupe (10 times magnification). Look at the stone face up, then from the side. Here are the cuts you most often find on antique rings.
The rose cut
This is one of the oldest. The stone has a flat base and a domed top, covered in triangular facets. It has no table, which means no large flat facet on top. Rose cut diamonds are often small and set as a surround, around a central stone or on marquise rings.
The cushion cut
It is also sometimes called an "old mine cut" or simply an old cut. The stone is square or rectangular with rounded corners, like a small cushion. It is often deep, with a small table and quite broad facets.
The old European cut
It is round, like a modern brilliant, and this is where people can get it wrong. The signs that set it apart:
- a small table compared with the diameter of the stone;
- a high crown, the part above the mount;
- an open culet: looking face up, you see a small circle or small octagon at the bottom (the culet), where a modern brilliant ends in a point;
- broader facets, which give "checkerboard" flashes rather than fine sparkles.
And the modern brilliant?
It has a large table, a lower crown and a pavilion that ends in a point. An antique ring may also carry a stone that was recut or replaced later. This is common and not a problem, but it counts in the valuation.
White gold or platinum: how can you tell?
Many antique diamond rings have a white mount. There are several possibilities.
- Platinum. In France, it is marked with a hallmark shaped like a dog's head, used since 1912. It is heavy, does not turn yellow and takes on a grey patina.
- 18 carat white gold. Like yellow gold of the same fineness, it carries the eagle's head hallmark. It is often coated with a thin layer of rhodium. When this wears off, a slightly yellow tint can show through.
- Silver on gold. On 19th century jewellery, diamonds were often set in silver laid over a gold base. The top is white and can blacken, the underside is yellow.
The hallmarks are usually inside the band or under the setting. They are tiny and often worn down by years of wear. Next to the fineness mark, there is sometimes a maker's mark in a lozenge shape, with the initials of the maker.
A ring with no readable hallmark is not necessarily worthless. It may have been resized, polished, or made abroad. In that case, a metal test settles the question. To learn more about marks, our guide to silver hallmarks explains how to read them with a loupe.
What we look at to value an antique diamond ring
The value of an antique ring is not just the weight of the gold. Several things come into play, and they work together.
The stones
This is often the main point. We look at the cut, the size of the stone, its colour (more or less white), its clarity (the small inclusions visible under a loupe) and any chips on the edges. A central stone with a good colour changes the valuation a lot. A row of small rose cuts counts mostly for the overall effect.
The period and style
A 19th century ring, a Belle Époque ring in finely pierced platinum, an Art Deco ring with geometric lines, a heavier 1940s ring in yellow gold: each period has its own style and its own collectors. Recognising the period helps to place the ring.
The work on the mount
Fine setting, even claws, careful piercing, an engraving inside the band: all of this shows quality work. The signature of a great jewellery house, when it is genuine, also matters.
The condition
We check the claws (a worn claw can let a stone fall out), the band (thinned, cracked, resoldered), missing or replaced stones, and signs of repair. A well kept ring, in its original condition, attracts more interest.
Papers and box
An old ring box, an invoice, an old laboratory certificate: keep everything. These help to date the ring and identify the stones. Our article on selling antique jewellery and how the price is set covers this in more detail.
Diamond or imitation: can you tell yourself?
Not with certainty. Old home tests, such as scratching a window or breathing on the stone, are not reliable and can damage the piece. Old imitations also exist: paste (a lead glass), rock crystal, or white stones such as colourless sapphire.
A professional uses a loupe, a diamond tester and experience of antique jewellery. Some simple testers can mistake moissanite, a synthetic stone, for diamond: this is why looking with a loupe remains important. For an important stone, a gemmology laboratory can give a full opinion.
Should you clean or repair the ring before showing it?
No. Do not have it cleaned with ultrasound, do not soak it in any product, do not have it repaired. A fragile stone can break, an old repair can give way, and a stone can come loose. Leave the ring as it is: that is the state in which we can read it best.
How does a valuation with Murier Antiquités work?
We examine the ring with you, without taking it apart. We look at the hallmarks, the cut of the stones, the mount and the condition, then explain what we see. The valuation is free and without obligation.
You can:
- send us photos on WhatsApp for a first opinion (one face up, one from the side, one of the inside of the band);
- show us the ring at home, in Paris and the Ile-de-France, where our visit is free;
- come to our stand at the Puces de Vanves at the weekend.
If you decide to sell, our antique jewellery buying comes with immediate payment, by bank transfer, as French law requires for gold and precious metals. And if the ring is part of a larger set of things, we can also give a valuation of your antiques at the same time.
A photo is enough to start
You have an antique diamond ring and want to know what it is worth? For a free valuation, call 06 24 56 38 58 (from abroad: +33 6 24 56 38 58) or send us photos of the ring on WhatsApp, on the same number. We will come back to you with a first opinion, without obligation.
