Jewelry design & manufacturing

A setting is the metal structure that holds a gem. Its design decides how much of the stone shows, how much light reaches it and how well it survives knocks. Prong settings, also called claws, bend thin metal arms over the girdle, the widest edge of the stone. GIA notes that six prongs hold a stone more securely than four and give the girdle more protection. Tiffany & Co. dates its raised six-prong solitaire to 1886 and says the setting is largely hidden so the diamond floats above the band. A bezel wraps a continuous rim around the girdle instead, trading side light for protection.

Other settings group small stones. In a bead setting, small pieces of metal are raised from the surface and act as prongs. Pavé, from the French for paved, sets stones so close that neighbors share a bead; micro-pavé does the same work under a microscope. A channel setting holds a row of stones between two parallel metal walls, and a halo rings a center stone with small ones.

Three settings hide metal. Niessing introduced its Spannring, or tension ring, in 1979; the shank alone grips the stone by spring pressure. Van Cleef & Arpels patented the Mystery Set in 1933, sliding grooved stones onto gold rails so no metal shows on the surface. A flush, or burnish, setting sinks the stone into a seat and presses the metal over its girdle.

Gold purity is stated in karats, where 24 parts out of 24 is pure gold; British usage spells it carat. Fineness gives the same ratio in parts per thousand, so 18 karat is 750. The UK Assay Offices recognize six gold standards: 375, 585, 750, 916, 990 and 999. Pure gold is too soft for most rings, so it is alloyed with silver, copper, zinc or palladium. More copper gives rose gold; white gold is usually finished with rhodium plating. Nickel is capped by law in the European Union and the United Kingdom: an article in direct and prolonged contact with skin may not release more than 0.5 µg/cm² per week, and a post inserted into a pierced ear no more than 0.2.

Platinum is dense, 21.5 g/cm³ against 19.3 for gold, and melts at 1,768 °C, so jewelers could work it freely only once high-temperature torches were available. In the United States the unqualified word platinum is reserved for at least 950 parts per thousand. Palladium (12.0 g/cm³, melting at 1,555 °C) has needed a UK hallmark since 1 January 2010. Sterling silver is at least 925 parts per thousand and tarnishes in air. Titanium (4.51 g/cm³) is light and strong but cannot be soldered at an ordinary bench, so titanium rings are machined from solid stock and are hard to resize.

Dealers and auction houses sort antique and vintage jewelry into periods named after British monarchs or art movements. The boundaries are conventions, museums date them differently, and styles overlap.

Georgian jewelry (1714–1837) survives in small numbers. The brilliant cut had arrived, and the V&A notes that diamonds were often mounted in silver to whiten their color; the largest jewels were worn on the bodice. Victorian jewelry (1837–1901) runs from archaeological revival gold by makers such as Castellani and Giuliano to naturalistic sprays, some with flowers set on springs so they shook as the wearer moved. Art Nouveau, which the V&A dates to 1895–1910, favored sinuous organic forms and put glass, horn and plique-à-jour enamel ahead of faceted stones; René Lalique and Philippe Wolfers are its best-known jewelers. The same years produced the garland style, a diamond and platinum re-reading of 18th-century design that dealers usually file under Edwardian.

Art Deco takes its name from the Exposition Internationale des Arts Décoratifs et Industriels Modernes held in Paris in 1925, although the label itself was coined in the 1960s. Dense concentrations of stones and sharp geometry mark it, and from about 1933 gold returned because it was cheaper than platinum. Since the 1960s independent jewelers trained at art college have used plastics, paper and textiles alongside precious metal.

The trade sorts jewelry into tiers by material, workmanship and price. No authority defines the tiers, and every boundary between them is convention. High jewelry, from the French haute joaillerie, means unique or nearly unique pieces built around exceptional stones, usually shown as themed collections by the Place Vendôme houses and a few Swiss firms. Van Cleef & Arpels says one Mystery Set clip takes about 300 hours at the bench and up to eight hours to cut each stone.

Below that, what a piece may be called is fixed by marking law. In the United States the Federal Trade Commission requires a karat mark beside the word gold, reserves the unqualified word platinum for 950 parts per thousand, allows Sterling only at 925 parts silver, and defines vermeil as a sterling silver base plated with gold of at least 10 karat to a thickness equal to 2.5 microns of fine gold. The UK Assay Offices set fineness standards and say nothing about price.

Below fine jewelry the trade says bridge or demi-fine for silver and vermeil pieces with small stones, and fashion or costume jewelry for base metal, plating, glass and cubic zirconia. Neither label is defined anywhere. Those materials are regulated for safety rather than quality: no individual part of a jewelry article may contain 0.05% or more lead by weight, and metal parts may not contain 0.01% or more cadmium.

The diamond engagement ring became a mass custom in the 20th century. Tiffany & Co. dates its six-prong solitaire to 1886 and calls it the engagement ring as we know it today. De Beers ran its first advertising campaign in the United States in 1939, and in 1947 Frances Gerety, a copywriter at the N. W. Ayer agency, wrote the line A Diamond is Forever.

A bridal set pairs the engagement ring with a wedding band shaped to sit against it. Solitaires, three-stone rings and halos are the standard designs, and platinum and 14 or 18 karat gold dominate because rings are worn daily and prongs wear down. The Knot Worldwide, surveying couples who married in 2025, reported an average engagement ring spend of US$4,600, an average center stone of 1.9 ct, and laboratory-grown center stones in 61% of rings, up from a much smaller share in 2020. De Beers reports that wholesale prices for laboratory-grown diamonds fell about 93% between 2020 and 2025, to roughly US$100 per carat, and that bridal buying now accounts for a quarter of natural diamond demand by value.

Who keeps the ring after a broken engagement depends on the jurisdiction. In England and Wales, section 3 of the Law Reform (Miscellaneous Provisions) Act 1970 presumes it an absolute gift, a presumption rebuttable by proof that it was conditional on the marriage taking place.

Marks struck into metal are a piece’s paper trail. A hallmark is an official guarantee of fineness applied by an independent assay office. The Goldsmiths’ Company dates British hallmarking to 1300, when a statute of Edward I required gold and silver to meet a defined standard and be marked with a leopard’s head. A statute of 1478 made the company answerable for substandard wares and required makers to bring work to Goldsmiths’ Hall to be marked, which is where the word comes from.

A current UK hallmark carries three compulsory marks: a sponsor’s mark, which identifies whoever is responsible for the article rather than its maker; a fineness mark in parts per thousand, compulsory in that numerical form since 1999; and the mark of one of the four assay offices, in London, Edinburgh, Birmingham and Sheffield. The date letter is optional. Articles below 1 g of gold or palladium, 0.5 g of platinum or 7.78 g of silver are exempt. The United States has no compulsory hallmarking; under the National Stamping Act a gold fineness mark may be out by three parts per thousand, or seven where solder is present.

A signed piece carries the name of the house that made or retailed it. Signatures raise auction estimates, which makes them worth forging, so specialists check construction and house archives rather than the engraving.

Most commercial jewelry now starts as a computer model. Designers build the piece in CAD (computer-aided design) software, which calculates metal weight, checks that prongs and walls are thick enough and places each stone to scale. The file goes to a 3D printer that builds a pattern in castable resin or wax, layer by layer, replacing much of the hand carving that wax modelers once did.

The pattern is then cast by lost-wax casting, a very old method. A copper amulet from Mehrgarh in Baluchistan, Pakistan, dated to about 4500–3600 BCE, is the oldest known object made this way; imaging published in Nature Communications in 2016 showed that its interlocking spokes could only have come from a wax pattern and that the smiths used unusually pure copper. Patterns are attached to a wax trunk to form a tree, encased in a plaster-like investment and heated until the wax burns out. Molten metal is then forced into the cavity by centrifugal force, vacuum or pressure. For repeat production, a rubber mold of a master model yields many wax copies. Some manufacturers skip casting and print gold or platinum parts directly by laser-melting metal powder.

A casting comes out rough. At the bench, jewelers cut off the sprues, file, solder, size shanks and polish. Setters then cut seats and work the metal over each stone under magnification.

Swiss high-end watchmaking, or haute horlogerie, treats gem-setting as a separate craft performed by specialized setters, many of them around Geneva. The work adapts jewelry technique to small, curved and functional surfaces: bezels lined with baguette-cut diamonds or sapphires, dials paved with brilliants, and cases and bracelets covered in snow setting, where stones of several diameters are packed so closely that almost no metal shows. Stones must be matched for color and calibrated in size so that crowns, pushers and crystals still fit and seal.

The word Swiss on a watch is regulated. Article 1a of the federal ordinance, revised with the Swissness rules and in force since 1 January 2017, requires that technical development take place in Switzerland, that the movement be Swiss and be cased up there, that the manufacturer’s final inspection happen there, and that at least 60% of manufacturing costs be generated there. The Federation of the Swiss Watch Industry adds that purely aesthetic stages, including design, may be done abroad, and that the bracelet is excluded from the 60% calculation, so a gem-set bracelet is judged on its own.

Watches and Wonders Geneva, where most of the large houses show new models, runs in April; the 2027 edition is scheduled for 5 to 11 April.