Fire Assay vs. XRF Computer Touch: Which Gold Purity Test is Right for You?
Computer Touch (XRF Spectrometry) - Fast & Non-Destructive
X-Ray Fluorescence (XRF) spectrometry shoots controlled X-rays into the sample, exciting the atoms of gold, silver, copper, zinc, and nickel. By measuring the secondary fluorescent energy emitted, the computer calculates the exact percentage composition.
Key advantage: 100% non-destructive. No metal is scraped, no stones are detached, and the turnaround time is under 10 minutes.
- Ideal for finished retail ornaments, antique jewelry, and quick spot checks.
- Turnaround: 5 to 10 minutes with instant printed report.
- Accuracy: 99.90% surface and cross-section precision.
Fire Assay (Cupellation) - The Global Gold Standard
Fire Assay involves taking a micro-sample of metal, wrapping it in pure lead foil, and heating it in a bone-ash cupel inside a muffle furnace at 1100°C. Base metals oxidize and absorb into the cupel, leaving a pure gold-silver bead.
This bead is then treated in nitric acid ('parting') to dissolve silver, leaving behind pure gold that is weighed on a micro-balance.
- Recognized globally as the ultimate standard for court disputes and bullion bars.
- Accuracy: 99.98% metallurgical precision.
- Turnaround: 45 minutes to 1 hour.
Essential Rules of Thumb
- Use Computer Touch (XRF) for retail jewelry you plan to wear or pledge as loan collateral.
- Choose Fire Assay for raw scrap melt, bullion trading, and commercial bulk batches.
- Both testing facilities are available under one roof at Rajendra Touch Lab in Kalyan.
Visit Rajendra Touch Lab in Kalyan (W)
Prakash Tower, Shop 11/A, Opp. Raja Hotel, Ahilyabai Chowk, Kalyan (W)
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