Black Friday Jewellery 2026 and How to Spot a Genuine Deal

Black Friday 2026 falls on Friday 27 November, with Cyber Monday on 30 November. For Black Friday jewellery, the number that matters is not the percentage on the banner but the "was" price beside it, and whether anyone ever paid it. That question now has teeth. Since April 2025 the Competition and Markets Authority has been able to fine a business directly for misleading shoppers, and in May 2026 the Advertising Standards Authority ruled against Black Friday savings claims run by John Lewis the previous November.

The checks below decide whether a Black Friday jewellery discount is real: the pricing rules, the gold price on the day, what the trade now pays for a laboratory-grown diamond, how the two certificate houses most buyers meet describe a stone, the hallmark, and the right to send a piece back. Every figure carries its date and its source.

Our 2025 look at Hatton Garden Black Friday offers named individual promotions. This year's piece names none, because the offers change every November and the checks do not.

How to tell whether a Black Friday jewellery discount is genuine

A Black Friday jewellery discount is genuine when the higher price was the piece's usual selling price, charged recently, for longer than the sale price, and through the same channel. The Advertising Standards Authority expects at least 3 months of pricing history to support a saving, and a manufacturer's RRP on its own does not prove one.

That standard comes from the ASA's advice on promotional savings claims, updated on 6 October 2026, and the rulings behind it are recent. On 20 May 2026 the ASA upheld complaints about two John Lewis laptop ads from Black Friday 2025. One showed a MacBook Air at £699 with a "£150 saving", but the implied £849 had been charged only in a few limited sales.

The other ad claimed a cut from £1,099 to £649 on 11 November 2025. Even 47 days at the higher price did not settle it, because the price had moved several times before. The John Lewis ruling concerns laptops, yet a ring is judged by the same test.

The penalties have changed too. Under the Digital Markets, Competition and Consumers Act 2024, the CMA can fine a business up to 10% of its global turnover for breaching consumer protection law, as the government announced on 7 April 2025.

No single formula decides the question, though. On 30 July 2026 the High Court refused the CMA's request to impose a fixed ratio of full-price to discounted sales on the mattress retailer Emma, and the CMA then temporarily withdrew its 2024 online mattress pricing guidance, according to Herbert Smith Freehills Kramer.

The practical check takes 2 minutes. Save a dated screenshot of any piece you are watching this week, so the was price on 27 November can be set against what the page showed in early November. Treat "up to 50% off" with care as well. The ASA's advice says that if fewer than 10% of items carry the maximum saving, the claim is unlikely to be fair.

What the gold price does to a discount on an 18 carat band

Take a plain 18 carat gold wedding band weighing 5 grams. An 18 carat alloy is 750 parts gold in 1,000. At 17.47 GMT on 4 November 2026, BullionVault's spot price for gold on the wholesale bullion market was £3,019.53 a troy ounce, or £97.08 a gram. The gold in an 18 carat alloy was therefore worth £72.81 a gram that evening, and the metal in the band £364.05.

That figure is a floor, not a fair retail price. The gap between metal value and ticket is labour, finishing, design, the hallmark and the retailer's margin. Dividing an asking price by the weight in grams shows how much of it the metal explains, so the weight is a fair question before any gold Black Friday jewellery purchase.

Heavier pieces move more. A 40 gram 18 carat chain held £2,912.40 of gold at the same spot price on 4 November 2026. A 5% move in gold before 27 November would shift that metal value by about £146 in either direction, before any discount is applied.

Gold pricing cuts both ways. A retailer that prices gold from the daily market can lower a ticket simply because gold has fallen, which is a lower price rather than a promotion. And "30% off" a piece priced well above its metal content leaves more room for a genuine reduction than the same label on a heavy plain chain, where the gold alone accounts for most of the price.

Why a laboratory-grown diamond reduction can be the market moving

The common advice is that a third off a laboratory-grown diamond pendant is a bargain worth taking.

Our own 2025 Black Friday jewellery piece reported just such a reduction: a laboratory-grown diamond pendant in 18 carat yellow gold, cut from £1,430 to £958.10 on a retailer's website in November 2025, a 33% saving at retail. Edahn Golan's wholesale price list, as reported by JCK on 10 August 2026, shows loose laboratory-grown diamond prices fell 26% across 2025, a further 14% year on year in the first quarter of 2026 and 13% in the second.

Golan's wholesale index is down 96% since he began tracking it in 2018, and the same JCK article cites Paul Zimnisky's May 2026 analysis putting retail markups on laboratory-grown diamonds at more than 80% above wholesale. A 33% cut in a year when the wholesale market fell 26% is not much of a saving against what the stone itself had become worth.

Size matters too. In the second quarter of 2026, wholesale prices for 2 carat round laboratory-grown diamonds fell 20% year on year while 1 carat rounds rose 1%, so a discount on a larger stone is the likelier to be the market moving. Resale makes the point harder. A retailer quoted by JCK described a 5 carat laboratory-grown diamond ring bought for $25,000 in the early 2020s as having no resale value beyond its mounting. Natural stones have softened as well, with De Beers' rough price index down 16% year on year in the first half of 2026, according to Anglo American's July interim results.

Disclosure is the other check. On 13 May 2026 the ASA upheld complaints against Novita Diamonds over Meta ads that used "diamond" without a clear qualifier such as "synthetic", "laboratory-grown" or "laboratory-created". A listing with "diamond" in the headline and the origin only in the small print is the problem the ASA ruled on. Our comparison of natural and laboratory-grown diamonds covers the wider choice.

What a GIA or IGI report says, and what it leaves out

The two certificate houses most buyers meet now describe a laboratory-grown diamond in different ways, and a Black Friday jewellery listing can blur the two.

Since 1 October 2025, the Gemological Institute of America has not given laboratory-grown diamonds colour and clarity grades. According to its press release of 26 August 2025, GIA now classes them as Premium, which on GIA's criteria means D colour, VVS clarity or higher and Excellent polish and symmetry, or Standard, which on GIA's criteria means E to J colour, VS clarity and Very Good polish at minimum.

A stone below the GIA Standard threshold receives no GIA assessment, and each assessed stone carries a girdle inscription reading "Laboratory-Grown" with its GIA number.

The International Gemological Institute takes the other route. IGI reports issued for laboratory-grown diamonds in 2026 still print a colour grade and a clarity grade from IGI, along with the growth method, CVD or HPHT. One IGI report from that period describes a 1.26 carat round with an IGI colour grade of I and an IGI clarity grade of VS2.

The comparison resolves to one test. If a listing in November 2026 describes a laboratory-grown stone as "GIA G VS1", the report predates October 2025 or the description is wrong. Ask for the report number, check it on the issuing house's own website, and match the girdle inscription under a loupe before paying. A report grades the stone on the day it was examined, and says nothing about the setting or the price. Our notes on how to verify a diamond certificate and on GIA and IGI certification go further.

Hallmarks and exemption weights to check before paying

A UK hallmark has 3 compulsory parts, according to Trading Standards' Business Companion guide, reviewed in July 2025:

• The sponsor's mark, the registered mark of the maker or the business that placed the piece on the market.
• The fineness mark, in parts per 1,000 inside a shape for each metal: 750 for 18 carat gold, 925 for sterling silver, 950 for platinum or palladium at that standard.
• The Assay Office mark. The 4 UK offices are London, Birmingham, Sheffield and Edinburgh, and each has its own symbol.

Below certain weights, a piece can legally be sold without one. The exemption weights are 1 gram for gold, 7.78 grams for silver, 0.5 grams for platinum and 1 gram for palladium. Where a piece contains more than one precious metal, the threshold is that of the most precious metal in it, according to the London Assay Office. Small Black Friday jewellery gifts, such as gold studs or a fine chain, can sit under the gold threshold, so ask the weight.

Above those weights, describing an unhallmarked article as gold, silver, platinum or palladium in the course of business is an offence. The London Assay Office says Trading Standards officers can seize such items, and that a fine of up to £5,000 per article may follow.

Every dealer must also display the British Hallmarking Council's dealer's notice in a conspicuous position, and online sellers use a shorter version known as dealer's notice B. A hallmark certifies the metal only, not the stone, the workmanship or the price. Our piece on how to read a UK hallmark shows each mark in detail.

Returning Black Friday jewellery bought online or over the counter

Black Friday jewellery bought online can be cancelled for any reason within 14 days of the day it arrives, under the Consumer Contracts Regulations 2013, and the retailer must refund within 14 days of getting it back or receiving proof it was sent. The right does not cover pieces made to the buyer's specifications or clearly personalised.

The 14 days run from the day after the goods come into the buyer's possession, under regulation 30. If the retailer never explained the right to cancel, the period can extend by up to 12 months, under regulation 31. The exclusion for personalised goods sits in regulation 28, which is why an engraved band or a ring made to order normally falls outside it. Ask in writing whether a resize counts before agreeing to one.

A retailer can deduct for handling beyond what a shop would allow, under regulation 34, so try a ring on and no more. Over the counter the position is different. A purchase made in a shop carries no statutory cooling-off period, so a change of mind depends on the shop's own returns policy, which belongs on the receipt. If the piece is faulty, the Consumer Rights Act 2015 gives a 30-day short-term right to reject under section 22.

Buying in person in Hatton Garden makes the checks above physical. The stone can be seen unmounted, the inscription read under a loupe, the hallmark examined and the piece weighed in front of you. Ask for a receipt that names the stone as natural or laboratory-grown and gives the report number, the metal fineness, the weight and the price paid. An independent valuation afterwards is a separate, paid step.

Before 27 November, save dated screenshots of anything on your list. Weigh any gold piece against that day's metal value. Set a laboratory-grown stone's Black Friday price against current listings for similar stones, not last year's ticket, and expect one with a GIA report issued since October 2025 to say Premium or Standard rather than give a colour grade. Check every report number on the issuing house's website before paying, look for the 3 compulsory hallmarks and get the returns terms in writing. A Black Friday jewellery saving is only as real as the price history, the report number and the hallmark behind it.