18K Gold Value Guide

The purity math behind 18K

18K gold is 18 of 24 parts pure gold, or exactly 75.0% gold by weight, with the remaining quarter made up of alloy metals. That higher gold content gives 18K a richer, warmer color than 14K and a noticeably heavier feel for the same size piece, which is a large part of why European and luxury jewelry houses build their collections around it.

Melt value math: grams x 0.75 x spot price per gram. An 8-gram 18K designer bangle at a $75/gram spot price comes to 8 x 0.75 x $75 = $450.00 in gold content alone — often just the floor of its actual resale value if the brand and design carry a premium.

Designer and European jewelry

18K is the legal minimum purity marketed as 'gold' in many European countries, so imported and European-made fine jewelry is almost always 18K rather than 14K. It's also the standard purity for most major designer houses selling in the U.S. — think Cartier Love bracelets, Tiffany settings, Van Cleef & Arpels pieces, and much of the estate jewelry that circulates through auction houses.

Because of this, an 18K piece is more likely than a 10K or 14K piece to carry meaningful value beyond melt. A signed, authenticated designer bracelet can be worth several times its gold content on the resale market, so identifying the maker matters as much as identifying the karat.

Hallmarks to look for

Look for '18K,' '18KT,' '750,' or '.750' stamped discreetly on a clasp, inside a band, or on a fastener. European pieces frequently use the three-digit '750' millesimal stamp instead of the karat number, and designer houses add their own maker's mark, serial number, or logo alongside it.

• '18K' or '18KT' — standard karat stamp
• '750' or '.750' — European millesimal fineness mark
• Designer maker's marks, serial numbers or logos stamped near the karat mark
• French, Italian or Swiss assay marks on older imported pieces

What to know before you sell

Never let an 18K designer piece be quoted on melt value alone without first checking for a maker's mark or signature — the difference between scrap price and authenticated resale price can be substantial. If you have original boxes, papers, or a receipt for a designer piece, bring them; provenance can support a higher offer.

Not every 18K piece carries a brand premium. Custom-made rings, unbranded estate pieces, and damaged designer items with missing stones or broken clasps are often priced on melt like any other karat, so it's worth an honest look before assuming a piece is worth more than its gold content.

Sell your 18K gold in Houston

Gold King evaluates every 18K piece for both gold content and any designer or brand premium before quoting a price, using the live spot price as the baseline. We've handled designer and estate gold from Houston collections since 2008.

Bring your piece — with box or papers if you have them — to 6809 Southwest Freeway, open daily 10:00 AM to 8:45 PM, or call 713-997-0875 first. Photo ID is required by Texas law for precious metal sales.