In a Sandton safe deposit box, a woman in her late fifties keeps three pieces of jewellery she has worn in rotation for almost twenty years. A Cartier Love bracelet in yellow gold, the original screw still in the supplied screwdriver pouch. A pair of Tiffany diamond studs. And a thin Pandora-style gold-plated bangle her daughter gave her one Mother’s Day, kept because of who gave it, not what it is.
She has never asked what the three pieces are worth today. If she did, she would discover that two of them have outpaced the average jewellery insurance valuation, and that the third is essentially decorative.
The difference between those outcomes is not, in the end, about the metal weight. All three pieces contain gold. The difference is about the brand on the underside.
The man whose company owns the brand on two of the three is South Africa’s wealthiest citizen. Understanding why his fortune sits where it does is the closest thing the country has to a free education in how jewellery actually retains value.
A ten percent stake, sixty percent of a fortune
According to Bloomberg’s Billionaires Index, Johann Rupert’s net worth in early 2025 hovered between $16.3 billion and $19.3 billion across the year, with a February peak that Billionaires.Africa described as the highest reading since Bloomberg began tracking his wealth in January 2013. A Richemont share-price rally late in 2025 lifted his fortune by a further $4.6 billion in a matter of weeks, as Spectator Africa reported at the time.
Almost all of that money sits behind one position. Rupert’s family controls roughly 10.18 percent of Compagnie Financière Richemont SA, the Swiss-listed luxury group, through a dual-class share structure that gives the family disproportionate voting rights. That single stake, on the same Bloomberg methodology, accounts for more than 70 percent of his total estimated wealth.
He is, in a literal balance-sheet sense, a jewellery and watch holding. Not a diversified portfolio that includes some luxury exposure. A luxury holding with some other things attached.
What Richemont actually sells
This matters because Richemont’s published segment reporting is unusually clear about where the money comes from. The group’s most recent full-year results, released in May 2025 and available on its investor relations site, break revenue into three segments. Jewellery Maisons (Cartier, Van Cleef & Arpels, and Buccellati). Specialist Watchmakers (IWC, Jaeger-LeCoultre, Vacheron Constantin, Piaget, A. Lange & Söhne, Panerai, Roger Dubuis). And Other (which includes fashion brands such as Chloé and Alaïa, along with writing instruments under Montblanc).
The Jewellery Maisons division, on Richemont’s own numbers, generates a clear majority of group revenue and a higher operating margin than either of the other two segments. Financial Times coverage of the May 2025 results put it bluntly: Cartier alone is worth more than the entire rest of the group’s brand stable combined.
That sentence is the whole story.
Cartier remains the engine of the group. The watch maisons trail. Everything else is rounding error.
Brand provenance as the underlying asset
When a household jewellery box is valued, the appraisal is usually broken into two numbers. Material value, the weight of gold and the carat weight of any stones, valued at current market prices. And brand or workmanship premium, the amount above material value that a buyer in the secondary market would pay for the piece because of who made it.
For most household pieces, the brand premium is zero. A 9-carat gold chain bought from a high-street jeweller in 1995, with no maker’s mark and no provenance documentation, is worth its melt weight and not much else. The Pandora-style bangle in the Sandton safe falls into this category.
For a small set of pieces, the brand premium is the dominant value. A Cartier Love bracelet bought new at retail in the early 2000s, with original packaging and the screwdriver, will routinely sell on the established secondary market today at or above the original purchase price in rands, even before adjusting for the gold weight underneath. Sotheby’s and Christie’s branded-jewellery auction results across 2023 to 2025 have repeatedly confirmed this pattern.
The Tiffany studs in the same safe sit in a softer version of the same category. Original boxing and certificate are needed. The brand premium is meaningful but smaller than Cartier’s. Bonhams’ regular branded-jewels sales in London and Geneva publish results that map this hierarchy cleanly.
The reason these brands hold value is not aesthetic. It is structural. Richemont’s marketing budget across its Jewellery Maisons division is, on its own financial disclosures, in the hundreds of millions of euros per year. That spend, sustained over decades, is what keeps the brand premium intact. A buyer in 2026 pays above gold weight for a Cartier piece because they have lived their whole life in a world where Richemont has spent very large sums of money making sure they would.
The maker’s mark test
For the household reading this with a jewellery box of mixed provenance, there is a simple practical test that the Rupert / Richemont story makes available.
First. Turn the piece over and look for a maker’s mark. A small set of brands, listed in any reputable jewellery valuation guide, carry meaningful secondary-market premium. The Richemont Jewellery Maisons list is short and reliable: Cartier, Van Cleef & Arpels, and Buccellati. Outside Richemont, the equivalent list is also short: Tiffany & Co., Bulgari, Harry Winston, Boucheron, Chopard, Graff, Mikimoto for pearls, David Yurman for designer-tier American work, and a handful of historic English houses like Asprey and Garrard.
Second. If the maker’s mark is from one of those houses, the original receipt, box, certificate of authenticity, or service record matters. Branded jewellery without provenance documentation routinely sells at a 20 to 40 percent discount to the same piece with full paperwork.
Third. If the maker’s mark is absent or from a brand outside this list, the piece is, for valuation purposes, gold and stones. It may be beautifully made. It may be sentimentally priceless. It will be valued at material weight.
This is not a judgement about taste. It is a structural fact about how the secondary jewellery market actually prices.
Why the same logic applies to watches
Richemont’s other major segment is Specialist Watchmakers. The same logic applies, in a slightly modified form.
A small set of watch brands hold value in the secondary market because their manufacturers have, across decades, deliberately constrained supply and invested in horological credibility. Inside Richemont, that list is short: Vacheron Constantin, A. Lange & Söhne, and Jaeger-LeCoultre’s higher complications. IWC and Piaget retain partial value, but at a different tier.
Outside Richemont, the equivalent list, drawing on the same auction-house results, contains Patek Philippe, Rolex (for specific references), Audemars Piguet (for the Royal Oak family), and a handful of independents. F. P. Journe. Philippe Dufour. A small number of recent independents that have built collector demand.
Almost everything else in a typical South African household watch drawer is decorative. That includes most fashion brands, most pre-quartz inherited watches without horological pedigree, and most modern smart watches.
It is not a fashionable thing to say. It is what Richemont’s segment reporting and the major watch-auction results, across the past decade, repeatedly demonstrate.
What the Sandton safe actually holds
The woman who keeps her three pieces in rotation does not need to do anything different on the strength of any of this. She wears them because she likes them, not because of what the secondary market would pay.
But she is, without knowing it, a customer of South Africa’s wealthiest citizen on two of the three. The Cartier bracelet sits inside Richemont’s most profitable division. The Tiffany studs sit inside its closest competitor’s portfolio. The Pandora-style bangle sits inside the same global jewellery market but on the other side of the brand-premium line.
The structural lesson of Johann Rupert’s fortune is that brand provenance, sustained across decades by very large marketing investment, is itself an asset class. The piece in the safe inherits a fraction of that asset class if its maker is one of the named houses. If it is not, the piece is, however lovely, simply metal and stone.
You are buying patience. Patience by the maison to keep the brand intact across generations. That patience is what the customer is, in the end, paying for.
A useful thing to do, before disposing of any piece of inherited jewellery, is to check the underside. Not because you should sell what you find there. Because you should understand what you actually have.
The maker’s mark, where it exists, will tell you. The Rupert fortune is, in one sense, the very long-form proof of why those tiny stampings are worth turning the piece over to read.