The Niton brand of handheld X-ray fluorescence (XRF) analysers, manufactured by Thermo Fisher Scientific, has become a workhorse instrument across the jewellery, scrap-refining, hallmarking, and related industries. Models such as the Niton XL2, XL3t, and XL5 Plus provide rapid, non-destructive elemental analysis of metals, alloys, and a wide range of other materials, allowing dealers, refiners, and assay offices to verify the composition of gold, silver, platinum, and base-metal alloys in seconds without sample preparation. The technology has materially changed daily practice in many parts of the trade.

How XRF works

X-ray fluorescence spectroscopy works by exposing a sample to X-rays from a small source in the analyser, which excite the inner-shell electrons of the atoms in the sample. As those atoms relax, they emit characteristic X-rays at energies specific to each element. The detector in the analyser measures the energies and intensities of the emitted X-rays and uses them to identify and quantify the elements present. The technique is non-destructive, requires no sample preparation for most metallic surfaces, and gives results in seconds for routine alloys.

Capabilities and limits

Niton analysers can identify and quantify gold, silver, platinum, palladium, rhodium, copper, zinc, nickel, lead, cadmium, and a wide range of other elements relevant to the jewellery and refining industries. Detection limits vary by element and matrix but are typically a few hundred parts per million for routine work and lower for trace-element investigations on the higher-tier models. Calibration for jewellery alloys is well established and documented in the manufacturer's library.

The principal limit is depth of analysis: XRF measures only the top layer of the sample (typically a few tens of micrometres for the energy range used in jewellery work). This means that gold-plated base-metal pieces can read as gold on a surface measurement, fooling the unwary user. Best practice for high-value verification involves either filing a fresh surface for measurement, or using the analyser's plating-detection mode (available on higher-tier instruments) to check for plating thickness mismatches.

Use in the jewellery trade

For retail jewellers, pawnbrokers, and refiners, Niton analysers have become a standard tool for verifying gold and silver purity at the point of purchase. The instrument confirms or contradicts the seller's representation in seconds; mismatches with claimed karat value (e.g., a piece sold as 18k that reads 14k) are immediately apparent. Refiners use the analysers to determine alloy composition for melt-and-recover operations, including precise yields of gold, silver, platinum, and other recoverable elements. Hallmarking offices in jurisdictions where XRF is accepted as a verification method use Niton or comparable analysers as part of their compliance workflow.

Restricted-element compliance

The analysers also detect lead, cadmium, and nickel content — elements regulated in jewellery in many jurisdictions due to toxicity or allergenicity. The European Union's REACH regulations, the United States' Consumer Product Safety Commission limits on lead in children's jewellery, and the EU Nickel Directive all rely in practice on XRF or similar elemental analysis for compliance. Niton analysers are widely used by importers, retailers, and customs authorities to screen for restricted elements.

Position in the market

Competing handheld XRF analysers come from Bruker (S1 Titan), Olympus (Vanta), Innov-X (largely absorbed into Olympus), and other vendors. The Niton brand, owned by Thermo Fisher Scientific since the early 2000s, has long enjoyed strong market share in jewellery and recycling applications. Pricing for new instruments runs from approximately twenty thousand US dollars at the entry tier to fifty thousand or more for top-tier instruments with full sample-preparation accessories and extended calibration libraries. Used and reconditioned instruments are widely available at meaningful discounts.

In the trade

For working dealers, the Niton or comparable analyser is now closer to a standard fixture than a specialist instrument. Buyers should expect that any reputable refiner or pawn operation has access to one, and that pieces being represented as a particular karat or alloy will be screened. The instrument does not replace assay-grade precious-metal verification (fire assay, ICP-MS) for high-value or contested cases, but for routine commercial transactions it provides ample confidence at a fraction of the cost.

Further reading

• Thermo Fisher Scientific — Niton XRF analyser range
• GIA — XRF and elemental analysis in gemmology
• International Gem Society — XRF for jewellery verification