Common Myths About Gold Purity — Debunked

Myths and misconceptions about gold purity, testing, and hallmarking are widespread in India. Some are rooted in outdated information; others stem from misunderstandings about how modern hallmarking works. Here are 12 common myths — and the facts.

Myth 1: "24K gold is the best for jewellery"

Fact: 24K gold (999 fineness) is 99.9% pure, but it is extremely soft. It scratches easily, deforms under pressure, and is impractical for most wearable jewellery. Most Indian jewellery is made in 22K (916), which contains 8.4% alloying metals (usually copper and silver) that provide the hardness and durability needed for daily wear. 24K is best suited for investment bars and coins.

Myth 2: "You can tell gold purity by its colour"

Fact: Gold colour is determined by the alloying metals, not the purity level alone. 22K gold can appear in different shades depending on whether copper (warmer, redder tones) or silver (lighter tones) dominates the alloy. White gold (typically 18K) uses palladium or nickel to achieve its colour. Only scientific testing — XRF spectrometry or fire assay — can accurately determine purity.

Myth 3: "The hallmark stamp can be trusted on its own"

Fact: Physical hallmark stamps can potentially be counterfeited. The definitive verification is digital HUID verification through the BIS CARE App. The app confirms whether the HUID is genuine and matches BIS records. Always verify digitally, not just visually.

Myth 4: "Hallmarking damages jewellery"

Fact: Modern hallmarking uses precision stamping and laser engraving techniques that apply the marks with minimal impact on the article. The marks are placed on less visible areas (inner surfaces, clasps, backs). BIS-authorized centres are required to handle articles carefully and return them in the condition they were received.

Myth 5: "22K gold is always 91.6% pure"

Fact: 22K gold should be 91.6% pure. However, without hallmarking, there is no independent verification. Studies and enforcement actions have found that non-hallmarked "22K" gold can contain anywhere from 18K to 21K equivalent gold. The hallmark is the only way to confirm that 22K really means 22K.

Myth 6: "HUID can be reused on different articles"

Fact: Every HUID is unique and assigned to one specific article. It is generated through the BIS online portal at the time of hallmarking and permanently linked to that article's test results. HUIDs cannot be transferred, reused, or reassigned.

Myth 7: "Gold doesn't need testing if bought from a reputable jeweller"

Fact: Even the most reputable jeweller's claim is not a substitute for independent laboratory testing. Reputable jewellers themselves rely on hallmarking centres for independent purity certification. The hallmark protects both the consumer and the honest jeweller.

Myth 8: "Heavier gold means purer gold"

Fact: Weight indicates how much metal the article contains, not its purity. A heavy brass article could weigh more than a light gold ring. Purity is about the proportion of gold in the alloy, not the total weight. That said, the specific gravity test (comparing density to pure gold) can provide a screening indication — but XRF is the reliable method.

Myth 9: "Hallmarking is expensive and increases jewellery prices significantly"

Fact: The BIS-prescribed hallmarking charge is approximately Rs. 35 per article (exclusive of GST). On a piece of gold jewellery worth Rs. 50,000 or more, this represents less than 0.1% of the purchase price — a negligible cost for independent purity certification.

Myth 10: "Old jewellery without hallmarks is always impure"

Fact: Jewellery made before the mandatory hallmarking era may well be of genuine purity — it simply wasn't tested and certified through the BIS system. Many traditional jewellers maintained high standards even before hallmarking existed. The difference is verification: without a hallmark, purity is a claim, not a certified fact. Old jewellery can be submitted for XRF testing at any BIS-authorized centre.

Myth 11: "BIS hallmarking is only for gold"

Fact: As of September 2025, BIS has launched HUID-based hallmarking for silver articles under IS 2112:2025, covering seven fineness grades from 800 to 999. Currently voluntary, silver hallmarking may become mandatory. BIS has also been discussing mandatory bullion hallmarking at the refinery level.

Myth 12: "The acid test is as accurate as XRF"

Fact: Acid testing (applying nitric acid to a gold streak on a touchstone) provides only an approximate estimate of purity, typically within 1–2 karats of actual. It is semi-destructive and depends on the tester's experience. XRF spectrometry achieves accuracy within 0.1–0.5% and provides objective, instrument-based results. Fire assay is even more accurate at 0.01–0.03%. For any meaningful purity determination, scientific testing is essential.

The Bottom Line

Gold purity is a matter of science, not appearance, reputation, or tradition. BIS hallmarking with HUID verification provides the objective, independent, digitally verifiable purity certification that replaces myths with facts.