Karat Testing and Why Accuracy Matters in the Jewelry Trade
In the jewelry trade, analytical accuracy is measured directly in money. A deviation of one part per thousand in fineness adds up to significant sums on kilogram-scale transactions. Here, an analyzer is less a quality control tool than a trading tool: the technical foundation of trust between buyer and seller.
The second decisive factor is not damaging the item. Traditional fire assay gives the highest accuracy, but it consumes the sample and takes hours. It simply cannot be used on finished jewelry, antique pieces or a customer's property. Nondestructive analysis is the only practical option in these cases, and today it is standard practice across the trade, from scrap buying to the retail counter.
Gold, Silver and Platinum Group Metal Analysis
Nondestructive elemental analysis gives the full alloy composition and karat value in seconds without touching the piece. Because it reports alloying elements such as copper, silver, zinc, nickel and palladium, not just gold content, it is also used to verify white and colored gold alloys. Identifying platinum and palladium items, checking silver purity and assessing solder joints separately are all done with the same technology. Enclosed benchtop systems allow small and intricately shaped pieces to be measured safely.
Plating Thickness Measurement and Product Verification
The same technology measures both the thickness and the composition of gold or rhodium plating. This pays off in two ways: plating consumption can be optimized in production, and plated items cannot be passed off as solid in trade. It also helps identify cases where a surface reading on a heavily plated item could be misleading.
Detecting Fillings and Counterfeits
A single surface reading is not enough to detect fillings made from metals close to gold in density, such as tungsten, lead or iridium. Comparing measurements taken at several points, checking density and bringing in complementary methods where needed creates a reliable screening process. Refinery-scale operations periodically verify field measurements against reference methods to keep the two in agreement.
Standards and Regulations in the Jewelry Industry
XRF analysis of precious metal alloys is defined by standards such as ISO 15093 and ISO 15096, and the reference fire assay method by ISO 11426. In Turkey, hallmarking obligations and the precious metals trade are governed by State Mint regulations and the rules of Borsa Istanbul's Precious Metals and Diamond Market. In import and export, the fineness standards of the destination country also apply.
Common Analysis Methods in Jewelry and Precious Metals
XRF Analyzers. Determine full alloy composition and karat value in seconds without damaging the piece. The standard analysis method across the trade, from scrap buying to the retail counter.
Coating Thickness Measurement. Measures the thickness and composition of gold and rhodium plating, used to optimize plating consumption and to verify products.
Optical Emission (OES) Spectrometers. Track input and output purity with high accuracy in refining and verify field measurements.
LIBS Spectrometers. A complementary method for fast alloy verification and light element determination.
Scanning Electron Microscopes (SEM). Enable detailed examination of piece structure, plating cross-sections and surface finish quality.
