What 10K gold is worth and how dealers price it
10K contains 41.7% gold, the lowest karat that may be sold as gold in the United States. It is very hard and scratch-resistant but tarnishes more than higher karats.
Look for the hallmark 417 or 10K. 10K is typical of US class rings and budget jewellery. US class rings are typically 10K and weigh 10–20 g; synthetic stones in them are removed and have no resale value.
Dealers weigh the piece, deduct stones and non-gold parts, and multiply the net weight by 0.417 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 12 g US class ring holds 5.00 g of fine gold. Enter 12 g and 10K in the calculator above to see its live melt value in GBP. 10K is below the minimum gold standard in several EU countries, so some buyers are less familiar with it — insist on a test result rather than a guess.
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.
Developers can pull the same figure programmatically: 10K gold price per gram API.