Diamond Nexus vs Lab-Grown Diamonds
Is a Nexus Diamond a real diamond? The clearest answer comes from Diamond Nexus’s own product pages, so that is where we start.
No. Diamond Nexus describes its own headline product as a diamond simulant, meaning a stone made to look like a diamond with a different chemical makeup. A lab-grown diamond is chemically diamond. Diamond Nexus sells its simulant, moissanite and real lab-grown diamonds side by side, so check which line you are buying from.
Every quotation below was read from diamondnexus.com on .
Three Stones, One Storefront
| Question | Diamond Nexus Alternative | Moissanite | Lab-grown diamond |
|---|---|---|---|
| Is it a diamond? | No — their own pages call it a diamond simulant | No — a different mineral entirely | Yes — chemically, physically and optically diamond |
| What it is made of | Not published by Diamond Nexus | Silicon carbide | Pure carbon |
| Hardness | Not published | 9.25 to 9.5 on the Mohs scale | 10 on the Mohs scale |
| Independent grading report | None referenced on their site | Not a diamond report | Yes — at Beyond Carat, an IGI report in the box |
| Sold by Diamond Nexus? | Yes, their headline line | Yes, a separate line | Yes, a separate line |
| Covered by their Lifetime Stone Guarantee? | Yes | Yes | No — their terms exclude lab-grown diamonds from it |
| Sold by Beyond Carat? | No | No | Yes, exclusively |
Rows describing Diamond Nexus come from their About, product, guarantees and customer-service pages, read on 19 August 2026. Beyond Carat is not affiliated with Diamond Nexus and this page makes no allegation about their conduct. Prices are left out of this comparison: lab-grown listings reprice weekly, and a figure printed here would be stale before you read it. For the stone-by-stone physics of the second column, see our moissanite versus lab-grown page.
What Each Side Does Better
Where Diamond Nexus wins
- A Lifetime Stone Guarantee. If their simulant or moissanite chips, cracks or discolours they replace the stone at no charge, for life. We do not offer anything like it
- Two Spa Days in the first year at no cost, plus one resizing inside that year of up to two full sizes
- An in-house workshop with jewelers in Milwaukee handling repairs and refinishing
- Trading since 2004, with BBB accreditation since 2007
- A lower entry price than ours, though at a half-carat centre stone rather than a full carat
Where Beyond Carat wins
- Everything we sell is a diamond. There is no simulant line and no chance of buying the wrong one
- An IGI grading report in the box on every stone, at every carat size
- A published floor of D, E or F colour, VVS or VS clarity and Excellent cut
- No cap on returns — Diamond Nexus limits you to four returned products in any twelve months
- Free worldwide shipping, insured, signature required on US orders
The first bullet on the left is the one people expect a competitor page to hide. It is real, it is published, and on that specific comparison we lose. Our lifetime warranty covers defects in materials and workmanship — a chipped stone is not covered.
What Diamond Nexus Says About Its Own Stone
The disclosure is on their About page
Diamond Nexus describes the Diamond Nexus Alternative, in its own words, as lab created — and then as a “diamond simulant that, among all simulants, most closely imitates the look and wear of a diamond, with two exceptions – it is absolutely perfect in every way, and it costs significantly less.” That sentence answers the question people actually type into a search box, and it comes from the company rather than from us.
Their customer-service page separates the catalogue into three destinations in a single line: one for the DiamondNexus Alternative, one for Moissanite, and one for Lab Grown Diamonds. So a shopper on that site can buy a simulant, a moissanite or an actual lab-grown diamond, and the product names sit close together. If you are checking a purchase someone else made, the product title is where to look — it carries the Alternative qualifier.
Bottom line: the answer is on their site. It is just not on the page most people land on first.
Grading words without a grading report
The simulant is presented using the vocabulary of diamond grading: Perfect, simulating a perfect diamond; Colorless, described as D colour; Flawless, described as IF clarity; and Ideal Cut. The same page puts the question of material this way: “Does chemistry matter to you? Because the DiamondNexus™ Alternative is superior to a mined diamond, the choice comes down to the chemistry of the stone.” The composition itself is not stated there.
We are reporting that as an observation about vocabulary, not as an accusation, and we are not repeating the third-party claims about what the stone is made of, because no primary source confirms them. The practical point for a buyer is narrower: those grades are not a laboratory report. A diamond laboratory does not issue reports on simulants. When we say D–F colour and VVS–VS clarity, an IGI report ships in the box saying the same thing, and you can check it against the inscription on the girdle.
Bottom line: ask what document arrives with the stone, not what adjectives are on the listing.
The 2019 FTC warning letter, stated precisely
On 2 April 2019 the Federal Trade Commission announced that it had sent warning letters to eight jewellery marketers. Five went to sellers of diamond simulants: Agape Diamonds, Diamond Nexus, MiaDonna & Co., Stauer and Timepieces International. The letters concerned advertising that might lead consumers to believe simulated jewellery contained mined or laboratory-created gems, and the letter to Diamond Nexus referenced its use of the phrase “contemporary Nexus Diamond”. The company’s position was that its Nexus diamond alternative language is clear and that customers understand they are not buying a mined stone.
Three qualifications matter, and leaving any of them out would misrepresent the situation. A warning letter is advisory: it is not an enforcement action, not a lawsuit, and not a finding that anybody broke the law. No FTC complaint, consent order, class action settlement or state attorney general action against Diamond Nexus was found. And the letters are seven years old. Read them yourself at ftc.gov.
Bottom line: a documented, dated, advisory letter — nothing more, and we are not going to pretend it is more.
Their BBB profile carries two things at once
Diamond Nexus holds an A+ BBB rating and has been BBB-accredited since 2007. The same profile also carries a Pattern of Complaints alert, with 29 complaints filed in the last three years and 5 closed in the last twelve months. Both facts live on the same page and citing only one of them would give a false impression, so here are both.
The complaint themes, all written by consumers rather than verified by the BBB, cluster around warranty scope — labour and repair fees charged despite a lifetime promise — stone durability, and plating wear. It is worth noting that the warranty theme is consistent with the published terms rather than contradicted by them: the Lifetime Stone Guarantee explicitly excludes shipping and labour costs, and excludes setting replacement, polishing and rhodium plating. Reading the exclusions before buying resolves most of it.
Bottom line: read the guarantee’s exclusion list, which is published and specific.
Which Stone Suits You
A simulant may suit you if…
- The look matters and the material genuinely does not
- A guarantee that replaces a chipped or clouded stone for life is worth a lot to you
- You want the largest possible appearance for the smallest possible spend
- You are buying a travel piece, a stand-in, or a second ring
A lab-grown diamond suits you if…
- You want the stone to be a diamond when a jeweler tests it in ten years
- You want a report from a named laboratory with an inscription you can match
- Hardness and long-term wear matter because it will be worn every day
- You would rather explain nothing at all about what it is
Our read: this is not a quality argument, it is a disclosure argument. A simulant bought knowingly, at a simulant price, is a perfectly sensible purchase — and Diamond Nexus backs its stones in a way we do not. The failure mode is buying one while believing it is a diamond. If you are unsure what you already own, take it to an independent appraiser rather than relying on a home tester.
Frequently Asked Questions
The Diamond Nexus Alternative is not a diamond. Their own About page calls it a diamond simulant that, among all simulants, most closely imitates the look and wear of a diamond. Diamond Nexus separately sells a lab-grown diamond line, and those stones are diamonds. The two are different products on the same site.
They do not publish a composition. Their product page describes the stone as a simulant and states that for most couples the chemistry of the stone matters less than the saving, but it does not name the material. Third-party guesses circulate online without a primary source, so we are not repeating them.
No independent grading report for the simulant is referenced on any Diamond Nexus page we read. The stone is described using diamond grading vocabulary — D colour, IF clarity, Ideal cut — but a simulant is not graded by a diamond laboratory, so those words describe an appearance rather than a report.
The FTC announced eight warning letters to jewellery marketers on 2 April 2019, five of them to simulant sellers including Diamond Nexus, about advertising that might imply a simulated stone contains a mined or lab-created gem. A warning letter is advisory. It is not an enforcement action and not a finding that anyone broke the law, and no FTC complaint, consent order or class action against the company was found.
On stone cover, outright. Their Lifetime Stone Guarantee replaces a simulant or moissanite stone that chips, cracks or discolours, for life, at no charge for the stone itself. Our warranty covers manufacturing defects only, so a chipped stone is the owner’s problem. They also run an in-house workshop and have traded since 2004.
Not if you know what you are buying and the price reflects it. A simulant is a different material with different hardness and different long-term wear, and it has no resale market as a diamond. The problem is never the stone, it is discovering after the fact that you thought you bought something else.
If You Want The Actual Stone
Read next: moissanite versus lab-grown diamonds, what a lab-grown diamond actually is, and IGI versus GIA.
Not Sure What You Own?
Book a free 30-minute video or phone call. We will talk you through what to ask an independent appraiser, whether or not you buy from us.
See also: Agape Diamonds vs Lab-Grown Diamonds · Moissanite vs Lab-Grown · Is Beyond Carat Legit?