Diamond Nexus

Diamond Nexus is a Wisconsin-based online jeweler built around one idea: nothing in the catalogue comes out of a mine. Its own about page sums up the pitch in one line: "no mined stones, always affordable and quality above all." Instead of natural diamonds, the site sells three materials side by side: lab-grown diamonds, moissanite, and its own trademarked Nexus Diamond alternative, a diamond simulant the company developed itself. For an expat in Zürich comparing a mined stone from a Bahnhofstrasse showroom against a lab-created option bought online, that focus is the whole reason to look here rather than at a generalist retailer.

What you get

The three stone types are not treated the same, which is worth knowing before you pick one. Moissanite and the Nexus Diamond alternative both carry a Lifetime Stone Guarantee: Diamond Nexus states plainly that it guarantees the quality of those two materials for life. Lab-grown diamonds sit outside that specific guarantee, since they are real diamond, chemically identical to a mined stone, graded to the company's own standard of F/G colour, VVS/VS clarity and Excellent or Ideal cut. On top of the stone guarantee, every piece carries a Lifetime Manufacturing Warranty covering defects in the setting and metalwork, separate from whatever promise applies to the stone itself.

Sizing is handled with a specific, published policy rather than a vague promise: one free resizing per ring within the first year of purchase, covering up to two full ring sizes from the original size. That matters more than it might on a domestic site, because an expat who buys online, loses or gains a bit of weight in year one, and can't easily pop into a Zürich boutique for a fitting still has a documented path back to the maker. Financing is available too, through Affirm and through PayPal's financing option, for anyone who would rather spread the cost than pay it in one transfer from a Swiss account, though the site doesn't publish specific rates or terms anywhere I could read directly.

What stands out

The moissanite itself is described in concrete terms rather than marketing fluff: the product page rates it at 9.25 on the Mohs hardness scale, durable enough for daily wear, which is a specific, checkable number rather than a vague claim of toughness. The catalogue splits cleanly into two paths: a large made-to-order selection where you choose the setting, metal and stone yourself, and a separate Ready to Ship collection of in-stock pieces for anyone who doesn't want to wait on a custom build. Neither page states a specific number of days for either path, so if timing matters for your date, ask before you order rather than assume.

Every product page also links to a bookable appointment, alongside a phone line and email address staffed on weekdays. Diamond Nexus doesn't operate a walk-in showroom network the way a Zürich jeweler does, so this appointment slot is effectively the closest thing to a consultation the site offers, even though nothing on the pages I found spells out whether it runs as a video call, a phone call, or something else. If a guided conversation before you commit matters to you, book one and see what format they offer rather than assuming.

How it compares

Where Diamond Nexus separates itself from a straightforward lab-grown-diamond retailer is the middle option: the Nexus Diamond alternative is neither a natural stone nor a lab-grown diamond, but a proprietary simulant priced below both, aimed at buyers who want the look without the cost of even a lab-grown stone. That third tier isn't something every online seller carries, and it widens the price range a comparison shopper can work with on one site rather than three.

Shipping, duty and returns from Zurich

This is the part that matters most for a Zürich buyer, and it deserves a direct answer rather than a hopeful one. Diamond Nexus confirms it ships internationally: its customer service page states that for international orders, shipping charges are calculated at checkout, and it separately offers free shipping on US domestic orders over $100 and to APO or FPO military addresses. What it does not do, on any page I could read, is name Switzerland specifically, publish a Swiss shipping cost, or state who is responsible for customs duty or import VAT when the parcel lands in Zürich. That silence is common among US retailers who treat international as one checkout setting rather than a country-by-country policy, but it means you should run your address through checkout before you commit, and budget for the fact that Swiss customs duty and a carrier handling fee typically apply on arrival regardless of what the seller charges for shipping itself.

The return side has the same gap. Domestically, the policy is a straightforward 30 days for an exchange, store credit, or a refund. Nothing on the site states whether that window or process applies unchanged to an order shipped to Switzerland, or who covers the cost of shipping a ring back across the Atlantic if it doesn't work out. Ask customer service to confirm both the international return process and who pays for the return leg before you order, not after.

Worth knowing before you order

Diamond Nexus's corporate history is more eventful than most of the sites in this category, and it's worth a plain mention rather than a footnote. Its former parent group, Forever Companies, went through financial trouble that became public in trade press: in a legal filing dated January 2025, its own attorney said the company had "been on the verge of insolvency for several months," and Forever Companies subsequently filed for dissolution. A successor entity, Diamond Nexus LLC, formed in December 2024, has continued running the same website, warranty and customer service under the same brand, and litigation over that asset transfer was still being reported on by trade press as recently as spring 2026. None of this has stopped the site from trading: it continues to take orders, post new collections and honour the guarantees described above. It's the kind of detail a cautious buyer sending money overseas should know going in, even though day-to-day service hasn't visibly changed.

Reputation evidence backs that up without being glowing. The company's main Better Business Bureau profile is an accredited, A+ rated business with an average of 3.15 out of 5 stars across 41 customer reviews, a decent but mixed record rather than a spotless one. Trustpilot shows an average score of 3 out of 5, though from only four reviews, too small a sample to lean on heavily either way.

Who it suits

Diamond Nexus makes the most sense for an expat who already knows they want a lab-created stone rather than a mined one, wants a wider price ladder than a single "lab-grown diamonds only" retailer offers, and is comfortable ordering from a US site without a Zürich fitting room to fall back on for the initial purchase. The published resizing and warranty terms go some way to cover you after the sale, which matters if you expect to be in Switzerland only a few years and don't want a ring that only a US jeweler can service.

The verdict is a genuine yes with homework attached: the range of stone types, the resizing policy and the two-tier warranty structure make this a reasonable option to put next to the mined-diamond houses on this list, provided you treat the checkout page, not this write-up, as the final word on what Switzerland will actually cost you in shipping and duty, and you get the international return process confirmed in writing before you pay.