What is XRF Testing? How X-Ray Fluorescence Checks Gold Purity Without Damage

XRF (X-Ray Fluorescence) is a non-destructive testing method used to analyse the elemental composition of gold and other metals using controlled X-ray energy. In gold loan valuation, XRF machines generate a purity report showing the proportion of gold, silver, copper and other metals present in jewellery. The purity assessment may form part of the valuation process used by regulated lenders while assessing eligible pledged gold jewellery, subject to internal policies and applicable RBI guidelines.

XRF Full Form and Meaning

The XRF full form is X-Ray Fluorescence. The XRF meaning refers to a scientific testing method used to identify the elements present inside a metal without cutting, melting or scratching it.

In x-ray fluorescence, the machine directs controlled X-rays towards the jewellery surface. The atoms inside the metal absorb this energy and emit fluorescent signals. Every element produces a unique fluorescent signature. Gold produces a different signal from silver, copper, zinc and other metals commonly used in jewellery alloys.

The XRF machine analyses these signals and calculates the percentage composition of each element present in the ornament. The result appears as a digital purity report or printed output.

This method is widely used in jewellery valuation because it provides a standardised and non-destructive purity assessment.

How Does XRF Work? The 4-Step Process

Understanding how XRF works helps borrowers understand how gold purity is assessed during valuation.

Step 1: Jewellery Is Placed Inside the Machine

The jewellery item is placed on the testing surface of the XRF machine. The machine directs controlled X-rays towards a selected area of the ornament.

The process does not involve scratching, cutting, melting or applying chemicals.

Step 2: The X-Rays Interact With the Metal

The X-rays interact with the atoms present in the jewellery. This interaction causes energy movement within the atoms of different metals.

Each metal responds differently based on its elemental composition.

Step 3: The Material Emits Fluorescent Signals

The excited atoms release fluorescent energy signals. Gold, silver, copper and zinc each emit different signatures.

This forms the basis of the XRF process and allows the machine to identify the elements present in the jewellery.

Step 4: The Machine Generates a Purity Breakdown

The detector inside the machine records the fluorescent signals and converts them into a digital elemental report.

The report generally displays:

• Au (Gold)

• Ag (Silver)

• Cu (Copper)

• Zn (Zinc)

The purity reading is displayed digitally and may also be printed for valuation reference.

In gold loan evaluation, lenders may additionally review hallmark markings, jewellery weight and physical characteristics as part of their internal assessment procedures.

Why XRF Is Widely Used for Gold Purity Testing

Modern lenders and NBFCs commonly use XRF gold purity testing because it provides a standardised and non-destructive method of evaluating jewellery purity.

Older testing methods have operational limitations.

In acid testing, the evaluator scratches the jewellery surface and applies nitric acid to observe the reaction.

Touchstone testing involves rubbing the ornament against a testing stone and comparing chemical reactions.

Fire assay testing provides highly detailed results but requires melting the sample completely.

By comparison, non destructive gold testing through XRF allows jewellery purity assessment without altering the ornament.

Another advantage in the XRF vs acid test gold comparison is that the machine generates a digital elemental report based on measured readings rather than visual interpretation alone.

Limitations of XRF Testing

XRF testing is widely used for jewellery valuation, but certain practical limitations remain:

• XRF primarily analyses surface composition

• Thick gold plating over another metal may require additional verification

• Dirt, polish or coatings may affect readings

• Lower purity metal mixtures may produce less precise results

For this reason, lenders may combine XRF readings with hallmark checks, weight verification and internal quality assessment procedures.

Reading Your XRF Result: What Do the Numbers Mean?

An XRF result gold report displays the percentage composition of metals present in the jewellery.

A standard XRF printout may look like this:

This example represents a typical 916 gold XRF reading, which corresponds to 22 karat gold.

The karat conversion generally works as follows:

The XRF purity reading directly affects the value of pledged jewellery during a gold loan assessment.

The valuation process commonly uses the daily IBJA gold rate for 999 purity gold and adjusts it according to the jewellery purity percentage.

Example of Gold Loan Valuation Using XRF

Suppose the following indicative values apply:

• XRF purity reading: 91.6%

• Indicative IBJA gold rate for 999 purity gold: INR 6,200 per gram

• Jewellery weight: 20 grams

• Applicable loan-to-value ratio subject to prevailing RBI guidelines and lender policy

Step 1: Calculate Purity-Adjusted Gold Value

INR 6,200 × (916 ÷ 999) = INR 5,685 per gram

Step 2: Calculate Total Indicative Gold Value

INR 5,685 × 20 grams = INR 1,13,700

Step 3: Apply Applicable Lending Ratio

The eligible loan amount may be assessed after applying the lender’s applicable loan-to-value ratio in accordance with prevailing RBI regulations, product category and internal risk policies.

Final loan eligibility may also depend on:

• Jewellery purity assessment

• Net eligible weight

• Applicable documentation

• Product category

• Internal lender assessment criteria

The above example is illustrative only and should not be interpreted as a lending commitment or guaranteed valuation outcome. This calculation explains why the XRF purity reading directly affects the valuation of pledged jewellery and the applicable gold loan per gram value.

XRF Testing in Gold Loans: How IIFL Uses It

At certain IIFL Finance branches, gold loan XRF testing may form part of the jewellery valuation process.

The valuation workflow generally includes:

• Jewellery submission by the borrower

• Placement of the ornament inside the XRF machine

• Digital purity assessment through x ray fluorescence analysis

• Review of the elemental composition report generated by the system

• Cross-checking of hallmark markings, where available

• Loan eligibility assessment based on purity, weight, applicable valuation methodology and lender policies

Under RBI gold loan regulations effective from April 2026, regulated lenders are required to maintain prescribed practices relating to valuation transparency, borrower disclosures, auction procedures and communication standards.

Applicable loan-to-value ratios, eligible loan amount and repayment terms depend on:

• Prevailing RBI guidelines

• Gold purity assessment

• Product category

• Internal lender policies

• Documentation review

Lenders may also conduct periodic calibration and maintenance checks for valuation equipment as part of operational quality-control procedures.

Conclusion

XRF testing gold valuation has become an important part of modern gold loan assessment because it provides a non-destructive and standardised method for analysing jewellery purity. By identifying the elemental composition of gold accurately, XRF systems support transparent valuation practices and help lenders assess pledged jewellery in line with applicable RBI guidelines, internal policies and operational quality standards.

Disclaimer : The information in this blog is for general purposes only and may change without notice. It does not constitute legal, tax, or financial advice. Readers should seek professional guidance and make decisions at their own discretion. IIFL Finance is not liable for any reliance on this content. Read more