By Rocco Clayfield, trading as GoldPaid; the business incorporated as GOLDPAID LTD (company 17382540) on 5 August 2026 · Published · updated
Found 750 on your piece? Send us a photo of it
Photograph the number stamped inside the ring or on the clasp, then the whole piece, and send both on WhatsApp. We will reply with what the mark means and a rough estimate of what we would pay. No obligation, and nothing needs posting.
No WhatsApp? Call 07944 014111, 8am to 9pm.
Not sure what the mark says? Use the hallmark lookup. Final offers depend on inspection, item weight, purity, hallmarks, stones, non-gold components, condition and the live precious-metal market.
The 750 number
18 carats in the 24-carat scale is 18 divided by 24, which is 75% by weight, or 750 parts per thousand. That is what the punch records: three quarters of the alloy is pure gold.
Typical recipes: 18ct yellow is roughly 75% gold, 12.5% silver, 12.5% copper. 18ct rose pushes the copper up. 18ct white uses palladium instead of silver, with rhodium plating for the bright finish.
Where you see 18ct
Signed designer jewellery, Cartier, Tiffany, Bulgari, Boodles, Boucheron, premium British and European retail brands, and most signed engagement rings sit at 18ct. The colour is richer because there is more pure gold, and the marketing weight of "fine jewellery" sits at this carat.
You will also see 18ct on heavy gents’ signets, on dress watches, on premium chains and on bullion-style jewellery items intended to hold both wear and value.
Wear, scratch and dent
How 18ct sells at scrap
Recovered gold per gram on 18ct is substantially higher than 9ct or 14ct because the gold percentage is twice that of 9ct. Refiners process 18ct routinely, the recovery yield is high, and the market for it is deep.
Where designer 18ct has resale value beyond the gold (a signed Cartier love bracelet, an antique 18ct mourning brooch, a rare watch), the piece is worth more sold whole than melted. A written XRF valuation gives you the scrap floor in writing so you can negotiate the resale price against that floor.
Final offers depend on inspection, item weight, purity, hallmarks, stones, non-gold components, condition and the live precious-metal market.
Identifying 18ct quickly
- Find the standard mark inside the shank or on the clasp.
- Look for 750 in a small punch with cut corners, or "18ct", "18K", "18kt" on imported pieces.
- Look for the matching UK assay office mark beside the standard (leopard, anchor, rose, castle).
- On signed designer pieces, locate the signature alongside the hallmark and document it for resale value research.
- When marks are gone, post it for XRF. Designer pieces benefit especially from the written report because it confirms metal content for any future resale.
Sending 18ct by post
18ct posts the same as any other gold carat. The XRF report shows the alloy and the weight, the bank transfer settles the offer, and decline is free tracked return. Your parcel travels on Royal Mail Special Delivery Guaranteed, tracked and signed for. Royal Mail cover may be available up to £2,500 depending on the postal method and cover level used. GoldPaid can confirm the appropriate postal option before you post. If the lot may be worth more than £2,500, tell us first and we can split it across more than one prepaid label at no charge. See how to sell gold by post.
Signed pieces are weighed and identified individually so you can choose to accept the scrap offer or withdraw the piece for a private resale.
Scrap floor, or resale price
18ct is where the gold market and the fine-jewellery resale market overlap most. The scrap recovery is generous because the gold content is high, but a Cartier bracelet on a signed plaque is often worth more sold whole. The right move depends on the piece. A written XRF report puts the scrap floor on paper so you can compare it to any auction estimate before you commit. That is the value of testing before selling, every time. For plain or broken 18ct with no resale story, selling it as scrap gold is the simpler route once it has been tested.