Stellini Diamonds

Stellini Diamonds runs a by-appointment showroom at Löwenplatz in Zürich, at Seidengasse 17, 8001 Zürich, a short tram ride from the old town rather than a storefront on Bahnhofstrasse itself. Giuliano Stellini started the business in 2018 after buying an engagement ring for his own partner and finding that the stone, sold to him as VS quality, still showed an inclusion he could see without a loupe. That gap between the certificate and what he was actually looking at became the pitch: sell diamonds with the grading explained up front, natural and lab-grown side by side, rather than leaning on a brand name to close the sale.

What's on Offer

The catalogue splits engagement rings by setting (solitaire, a ring with lateral stones, trilogy, halo), by metal colour (yellow, white or rose gold, or platinum), and by stone shape, with round, oval, pear, radiant, marquise, emerald, cushion, asscher, heart and princess cuts all listed separately. Settings use 18-karat gold or 950 platinum, described on the site as nickel-free. Beyond engagement rings there is a wedding-ring line and a Fine Jewelry range covering earrings, bracelets, necklaces and rings, plus a custom-made option if you want a design built from scratch rather than picked off the shelf. Everything is made in Switzerland rather than assembled from imported settings.

Certification and the Four Cs

Every stone is graded on the standard four Cs, carat, cut, colour and clarity, and Stellini is specific about what it actually stocks rather than the full range those scales allow for. Colour runs from D, the whitest grade, down to Z, visibly tinted, across the industry; Stellini only carries D to F, the colourless end of that scale. Clarity runs from flawless down to heavily included; Stellini's stock starts at VS and goes up from there, and cut is Excellent only. Natural diamonds are certified exclusively by GIA, the Gemological Institute of America. Lab-grown stones carry GIA or IGI (International Gemological Institute) paperwork depending on the piece. The site is upfront that telling a lab-grown diamond from a natural one by eye is close to impossible even for a trained jeweller, because a lab-grown stone is chemically and physically identical to a mined one: the same hardness, the same density, the same way it bends and reflects light. The two production methods it describes are HPHT, where a diamond seed grows under very high pressure and heat, and CVD, where carbon from a gas, usually methane, builds the stone up layer by layer inside a chamber. The practical difference for a buyer is price: the site states that lab-grown stones run 30-50% cheaper than a comparable natural diamond, since there is no mining or extraction cost behind them.

Booking an Appointment

The showroom only opens by appointment, which keeps a visit a genuinely private consultation rather than a walk-in counter, and it means booking ahead rather than turning up on spec. A search of the business's own booking system turned up a free showroom consultation and a one-hour engagement-ring consultation over WhatsApp video as options, though the booking page itself did not load cleanly enough on a direct check to confirm every detail, so treat that as a starting point to verify when you actually book rather than a fixed offer. A video option matters if you are new to Zürich and still deciding whether a special trip across town is worth it, or weighing Stellini against a maison boutique before you have settled in properly.

One thing worth knowing before you rely on the site's English: the language switcher lists German, French, Italian and English, and the pages that matter for a buyer, the about page and the diamond-education pages among them, read cleanly in English once you land on them. The homepage is a different story. Even under its own English address, several of the headline taglines and section labels still show up in German rather than English. It is not a dealbreaker, since the pages that actually explain the product and the policies are properly translated, but do not expect the landing page itself to read as fully English on first glance.

Price and Ways to Pay

Prices sit directly against each ring in Swiss francs, not hidden behind a request-a-quote form, which matters in a category where price transparency is often the whole difference between dealers. Starting prices on the site run from CHF 2,790 for the Sofia in yellow gold up to CHF 6,900 for the Victoria in either yellow gold or platinum, with plenty in between: Positano from CHF 2,990, Cinderella from CHF 3,100 in white gold or CHF 3,250 in yellow gold, Grazia from CHF 3,250, Mirabella from CHF 3,980, and Elisa in platinum from CHF 4,490. Those are setting prices; swapping in a bigger or higher-grade stone moves the final number, and the site does not pretend otherwise about that.

If you would rather not pay it all at once, Stellini offers 0% interest financing through a provider called Heylight, split across 3 to 12 monthly installments, for purchases up to CHF 10,000. The first installment is charged at checkout and the rest is billed automatically to your card each month, tracked through your own Heylight account. That is a genuinely useful option for someone building a life in a new city who would rather not put a whole relocation budget into one purchase.

Shipping and Buying From Outside Switzerland

Worldwide shipping is stated on the site, and checkout itself lets you pick Switzerland (CHF), Germany, France, Italy, Austria (all in EUR) or the United Kingdom (GBP) as a destination and currency. That is a reasonable spread for an expat audience: order from Zürich and ship home, or set the currency to your home country while you are still deciding whether the trip to the showroom is worth making at all. For a destination outside that list, the site does not spell out how customs or duty is handled, so that is worth a direct question rather than an assumption if you are shipping somewhere further afield.

After You Buy

Ring sizes change, especially if you are only in Switzerland for a few years and your circumstances, or your finger, shift in the meantime. Stellini's stated policy, repeated identically on both the homepage and the financing page, is 90 days of free ring-size adjustment after purchase, alongside a right of return. One of the site's own city landing pages states a 30-day window instead, which does not match the 90-day figure given everywhere else, so it is worth confirming which applies at the time you buy rather than assuming the shorter one still stands.

Track Record

This is not only a landing page with no footprint beyond its own marketing. Giuliano Stellini was interviewed by the Swiss outlet 20 Minuten (20min.ch) in a piece published in November 2025 about celebrity influence on engagement ring trends. He told the paper that close to 60 percent of the stones he currently sells are oval cut, up sharply from a few years back, and that buyers who once typically chose a half-carat stone now commonly choose a two-carat one. He put part of that shift down to lab-grown pricing making bigger stones reachable, citing a gap of roughly CHF 30,000 for a lab-grown stone against over half a million francs for a comparable natural one at the top end. He also told the paper that his stones, both natural and lab-grown, are sourced through dealers in India. None of that comes from Stellini's own marketing copy; it is a third party asking him about his actual trade, which is a reasonable sanity check that this is a working jeweller and not just a storefront with a nice photograph.

Who It Suits

Stellini suits a buyer who wants the grading explained rather than assumed, and who would genuinely consider a lab-grown stone instead of treating natural as the only serious option. The appointment-only format and the video consultation route both work well for someone who is new to Zürich, still learning the city, or short on time before a trip home. Someone who wants a heritage maison with a shopfront on Bahnhofstrasse and generations of house history should look elsewhere in this category; Stellini's whole pitch runs the other way, buying stones directly and putting the saving into the diamond rather than the address. For an international buyer who wants CHF pricing up front, a certificate they can check against an independent lab, and financing that spreads the cost without a long Swiss credit history, it is a solid stop before committing to anything bigger on Bahnhofstrasse.