What 12K gold is worth and how dealers price it
12K is exactly half gold. It is rare as solid jewellery today, but the figure 12K often appears on gold-filled items (for example '1/20 12K GF'), which contain only a thin gold layer.
Look for the hallmark 500 or 12K. 12K is typical of antique pieces and some gold-filled items. A '12K GF' or '12K RGP' mark means the item is not solid gold; its scrap value is a small fraction of solid 12K, often close to zero at retail buyers.
Dealers weigh the piece, deduct stones and non-gold parts, and multiply the net weight by 0.5 to get the fine gold content. They then multiply by the GBP spot price per gram and apply their payout percentage — usually 60–75% of melt at shops and pawnbrokers, 80–90% at specialist buyers.
Worked example: a 5 g solid 12K antique ring holds 2.50 g of fine gold. Enter 5 g and 12K in the calculator above to see its live melt value in GBP. Check for GF, RGP or 'rolled gold' next to the 12K stamp before calculating — the calculator assumes solid gold.
In the UK, gold dealers must be registered for anti-money-laundering supervision and check ID. Hallmarks are enforced by the Assay Offices in London, Birmingham, Sheffield and Edinburgh, which makes British marks among the most reliable.