How to make gold: visiting the Chopard Gold Foundry

We recently had the opportunity to visit Chopard’s gold foundry in Meyrin in the Canton of Geneva, Switzerland. And bring you this inside peek at one of the most elusive of manufactures.

How to make gold: visiting the Chopard Gold Foundry

Gold. What a material. Precious. Rare(ish). Amazingly beautiful. In its pure form of 24K (999 parts out of 1000), it is too soft to be used for watchmaking. At this purity, the metal is almost too malleable. Made into a bracelet it would stretch with wear. Made into a case, it is so soft that it would dent, scratch and even morph shape over time. Thus, the standard used for jewellery and watchmaking is 18K gold. This is an alloy containing 750 parts of 1000 of gold in combination with other metals:

• 18k Yellow Gold: This type of gold has brighter orange-yellow tones. It is created by mixing 75% pure gold with 25% of other metals such as copper and silver.
• 18k White Gold: This type of gold has a warm white appearance. It is made by mixing 75% pure gold with 25% of other white metals such as nickel, silver, or palladium.
• 18k Rose Gold: This type of gold has a unique reddish-pink hue that is achieved by mixing 75% pure gold with 25% of other metals such as copper and silver. The copper content is higher than yellow gold, giving the redish hues.

Among the watchmaking maisons, having the ability to smelt gold in-house is quite rare. Much rarer than in-house movements. As far as we know, other than Chopard, only Rolex and Hublot have their own gold foundries. Each of these have decided to do their own gold for their own reasons. Rolex to produce their unique alloys which they call Everose – their version of 18K rose gold which according to them, resists tarnishing more than regular rose gold. And as they needed the foundry to smelt Everose gold, they use the same for white gold and yellow gold which they use. Hublot needed theirs for their Magic Gold, an 18K variant which is claimed to be more scratch resistant than regular 18K gold.

And Chopard. Their need is far more noble. Their foundry has given them the ability to be the only watchmaker who use ethical gold exclusively in all their watches and jewellery, since 2018. Ethical gold is gold which is responsibly and ethically made. From the mines, to the refining to the smelting into the alloy. Every step is traceable.

Karl Scheufele, father of the current co-presidents Caroline and Karl-Friedrich Scheufele, had the visionary idea of achieving vertical integration of production, starting with the smelting of gold. This was way back in 1978. While the first furnace he acquired has since been replaced by a state-of-the-art model, complete with innovations enabled by computer science, the principle remains the same.

The foundry

The foundry is in the basement of Chopard’s vast complex in Meyrin, behind closely guarded and ultra-secure doors, is a place that resembles the lair of a 21st century alchemist. It is here that the Maison’s artisan Paulo smelts the Chopard gold and produces all its alloys. All gold used by the Maison is smelt here.

We met Paulo in his foundry recently, and found him to be a true alchemist. Captivated and passionate about his craft. He makes ingots that are used by the manufacture.

“Some people see me as an alchemist because I transform precious metals, while ensuring that Chopard gold is 100% Ethical. The fact that I can claim that people out there are wearing a watch or a piece of jewellery made from my gold makes me feel that in some way, I help to make their dreams come true”

Paulo

The process starts with Ethical Gold. This is delivered to the Maison as little pellets from the Swiss Better Gold Association and marked as Ethical Gold. Chopard has chosen not to use the typical 1kg ingots of 999 gold made for the banks. For example, 999.999—six nines fine: The purest gold ever produced. Refined by the Perth Mint in 1957, or the more regular 999.9 1kg bar shown below for Suisse banks. The reason why the gold ingots used by Chopard is not the regular ingots from banks is because these do are now tracked throughout the process from mining to manafucture. And to qualify as Ethical Gold, the entire chain of custody must be certified. This costs more, but it ensures that fair conditions by people who enjoy economic and social protection while working in secure mines. For more information on Chopard’s ethical sourcing philosophy and practice, click this link.

Paulo starts by putting the gold pellets into a crucible inside a vacuum furnace.

The furnace is heated to 1000°C by an induction coil which melts the gold, silver and copper to make the alloy. To make an 8 kg ingot of 18K gold, 6kg of pure gold pellets and two kilos of alloys are used. For 5N gold, 1.5kg of copper and 0.5kg of silver is used. This gives the alloy the red colour.

If less copper is put in, then more silver is added, making the gold more yellow. To obtain white gold, no copper is used, but silver and sometimes nickel is used. In the Chopard foundry, palladium, a metal which is more precious than platinum, is added to ensure that the 18K White Gold product does not tarnish easily. Some foundries use no palladium, and watch cases which use this 18k White Gold are often rhodium plated to prevent tarnishing.

The mixture is molten in the crucible, and poured into a mould to obtain an ingot.

This ingot is immersed in cold water to crystallise and the metal hardens to the desired 150 Vickers hardness.

The ingot is then pressed by a roller mill and stretched into a longer bar. This stretching also increases the hardness to 210 Vickers. For the high jewellery pieces, Maison Chopard uses another method to obtain the objects. This is done by casting into a prefabricated mould in the negative impression of the object. As the gold is then not rolled, it is not subsequently hardened.

Before leaving for the workshops, each bar is numbered and a gold sample is taken from each one. It is then sent to the Precious Metals Control (PMC) office which analyses the sample and sends a certificate with the title of the gold accordingly. The precious material can then go into production. 

Every day, between seven and eight ingots leave the workshop, depending on demand.