By Rocco Clayfield, Founder & Director, GoldPaid Ltd · Published 24 August 2026
What 15ct and 12ct actually mean
Gold carat (or karat) is a fraction of 24. 24ct is pure gold. 18ct is 18/24, or 750 parts per 1000. 15ct is 15/24 — 625 parts per 1000. 12ct is 12/24 — 500 parts per 1000, so half gold and half alloy metals like copper and silver.
Both standards were introduced in the UK in 1854 alongside 9ct, when the Hallmarking Act was amended to legalise lower-carat gold for jewellery. Before that, 22ct and 18ct had been the only permitted British standards. The change let jewellers make more durable, more affordable pieces — and 15ct in particular became the workhorse carat of Victorian and Edwardian jewellery.
The 15ct and 12ct standards were withdrawn in 1932 and replaced by a single new intermediate standard: 14ct (585 parts per 1000), which is still current today alongside 9ct, 18ct and 22ct. After the changeover, no new British pieces were legally hallmarked as 15 or 12 — so any mark you see is pre-1932, roughly 94 years old at the youngest.
How to spot the marks
The number is the giveaway. Look for a small punch with either the carat figure, the fineness figure, or both:
- 15ct: punched as 15, .625, or 15.625 in a shaped shield.
- 12ct: punched as 12, .5, or 12.5.
- Alongside the fineness, expect an assay office town mark (leopard's head for London, anchor for Birmingham, crown for Sheffield, harp crowned for Dublin, castle for Edinburgh), a date letter, and a small sponsor's mark showing the maker or retailer.
If the mark is worn, a loupe (10x) and daylight help. Do not scrub the piece — silver polish and cloth wear the punches away fastest.
What 15ct and 12ct pay at scrap
Scrap price is a direct function of gold content. The rough sums, based on the daily London spot price per gram of pure gold:
| Carat | Fineness | Approx. scrap % of spot per gram |
|---|---|---|
| 22ct | 916 | ~91.6% |
| 18ct | 750 | ~75% |
| 15ct | 625 | ~62.5% |
| 14ct | 585 | ~58.5% |
| 12ct | 500 | ~50% |
| 9ct | 375 | ~37.5% |
These worked examples use a hypothetical spot of £110 per gram of pure gold, which is close to the current basis: 15ct at 62.5% comes out at roughly £68.75 per gram of finished piece and 12ct at 50% at roughly £55. Actual paid rates sit a few per cent below spot to cover refining, assay and processing — the site's live per-gram rates by carat update every build, so use them rather than the illustrative numbers below for a firm sense.
For a typical Victorian 15ct locket weighing around 8–10 grams, that puts the metal value at £550–£688 on the £110 basis. For a heavy 15ct Albert chain at 30–40 grams, £2,063–£2,750. Those numbers move with spot, so treat them as illustrative rather than a quote — the live per-gram figure on the day is what any actual offer follows.
Not sure how any of this applies to your own items? Send a photo on WhatsApp and ask. We answer honestly, there is no obligation, and nothing is posted until you decide. Or call 07944 014111, 8am to 9pm, 7 days a week.
When the antique beats the scrap
Auction premium tends to appear when you have one or more of these:
- A clear maker's mark (sponsor's initials) alongside the assay marks.
- Period design with intact detail — Etruscan-revival granulation, seed pearls, guilloché enamel, mine-cut diamonds still in their original settings.
- Original fitted case with retailer's name (Asprey, Mappin & Webb, Garrard, a good regional jeweller).
- Named provenance — a documented family history or engraving that ties it to a person or event.
If any of these apply, a specialist jewellery auctioneer (Woolley & Wallis, Fellows, Bonhams, Tennants, a good regional saleroom) will value it free. Sending photos by email is enough for a first steer. Only send to scrap once you know what you have.
The pieces where scrap wins
Scrap is usually the honest answer when:
- The piece is broken, snapped or has lost its clasp and you would not wear it repaired.
- It is a plain 15ct or 12ct chain link, band or bar with no maker mark and no distinctive design.
- The stones are missing, damaged or clearly of low value.
- It is one of a dozen similar items from a house clearance and the metal value materially outweighs the auction hassle.
A snapped 12ct Albert chain at 20g on a £70 spot day pays around £700 at scrap, cleared into your bank the same working day. An auction sale of the same chain would probably estimate £450–£650, less 15–25% seller's commission, less lotting time, minus VAT on the buyer's premium. The metal route wins on plain broken jewellery almost every time.
How our process handles antique carats
When a pre-1932 marked piece arrives with us, we do three things before quoting:
- Read the hallmark under magnification and record the assay office, date letter and sponsor's mark.
- Test the metal in-house with XRF (X-ray fluorescence). This confirms the actual fineness — a piece marked 15ct should return around 62.5% gold; if XRF disagrees with the punch, we flag it and explain.
- Flag anything with obvious collector interest before we quote scrap. If your grandmother's 15ct pendant looks like it belongs in a saleroom rather than a crucible, we will say so and return it free of charge for you to pursue an auction valuation.
A quick note on other unusual marks
While you are looking, you may also see:
- 22ct wedding bands — common in Victorian and early 20th-century marriage rings, still the traditional Indian standard.
- Foreign fineness marks — 750 (18ct), 585 (14ct), 375 (9ct) without a UK assay office punch. Legal to sell, tested by us on arrival.
- Pinchbeck and rolled gold — brass alloys and gold-plated base metals that resemble gold but are not. Often marked rolled gold, RG, GF (gold-filled) or unmarked. These have almost no scrap value.
- 9ct on later pieces — the youngest gold standard, introduced in 1854 alongside 15 and 12, and still current.
Our full hallmark guide walks through the assay office punches, date letters and standard marks in order.
If you want to sell
For plain 15ct or 12ct scrap, our antique gold and postal selling pages walk through the process. Cover may be available up to £2,500 depending on the Royal Mail postal method and cover level used — Special Delivery is the usual choice. Once your parcel arrives, we weigh, XRF-test and offer within the working day. Faster Payments land within one working hour of acceptance. If you decline the offer, return is free and tracked.
If the piece looks interesting, we say so before quoting. If it does not, we pay honestly on metal. Call or WhatsApp Rocco on 07944 014111 (8am–9pm, seven days) with a photo of the mark if you want a steer before posting.
Common questions
Is 15ct gold real gold?
Yes. 15ct is 625 parts pure gold per 1000, alloyed with copper and silver for strength. It was a legal British hallmark standard from 1854 until it was withdrawn in 1932.
Why did the UK stop using 15ct and 12ct?
The two standards were considered too close together, and the assay offices wanted a single intermediate carat. In 1932 both were replaced by 14ct (585), which sat neatly between 9ct and 18ct. Existing 15ct and 12ct pieces remain legal to own and sell.
Can I sell a 12ct piece if it has no hallmark?
Yes, but expect it to be tested. Foreign pieces and some Victorian imports lack UK hallmarks. We XRF-test every item on arrival to confirm the actual fineness before quoting.
Is a 15ct piece worth more than a 14ct piece?
Per gram at scrap, yes — 15ct has more gold content (625 vs 585). But 14ct pieces are usually newer, in better condition and less likely to carry antique premium, so a like-for-like weight comparison is rare.
How can I tell if my 15ct piece has collector value?
Look for a maker's mark (2–4 initials in a shaped shield), original fitted case, intact enamel or stonework, and any period design detail. Photograph the marks and email a specialist jewellery auctioneer for a free steer before scrapping.
Do you buy 15ct pieces even if the hallmark is worn?
Yes. Worn marks are common on Victorian and Edwardian jewellery. Our XRF test confirms the fineness regardless of how legible the punch is.
What if my piece turns out to be 9ct not 15ct?
We test everything on arrival. If your piece is actually 9ct, we quote you at 9ct rates and tell you why. You can accept, decline or ask for it back — return postage is free.