How to Check the Purity of 20-Carat Gold

• 20 carat gold purity percentage is 83.3%, combining purity and durability for jewellery.
• Look for the official 20 carat gold hallmark sign for authenticity.
• Use tools like a gold wastage percentage calculator to verify gold quality.
• Simple methods such as the Magnet, Float, and Density Tests help in how to calculate wastage in gold and purity.
• Since July 2021, the BIS hallmark on 20-carat gold shows only three marks: the BIS logo, the 20K833 purity grade, and a unique six-digit HUID number.
• Under the RBI's 2025 gold-loan framework (in force from 1 April 2026), you can borrow up to 85% of your 20-carat gold's value on small-ticket loans.

Gold has always been a symbol of wealth, beauty, and tradition. When you decide to invest in 20K gold , ensuring its authenticity and purity becomes crucial. With counterfeit gold on the rise, learning how to check the purity of 20-carat gold ensures you make smart investment choices and don’t overpay. Moreover, owning genuine 20K gold not only adds value to your personal collection but also enhances your ability to avail a gold loan against it, providing quick financial assistance when needed. Let’s explore simple, effective methods to verify your gold’s purity.

Before you buy or pledge, it helps to know how 20-carat gold is priced. Most Indian jewellers quote daily rates only for 22K and 24K, so 20-carat gold does not have a separate 'sticker' price. Its value is derived from the 24-karat rate because 20-carat gold is 83.3% pure; its price works out to roughly 83.3% of the prevailing 24K rate per gram before making charges and applicable GST.

The gold price changes every day and every minute. Moreover, it can also vary across cities. The gold price today, 9th July 2026, at 12:30 pm and in Mumbai is as follows:

• 24 karat gold - ₹14,368
• 22 karat gold - ₹13,161

Understanding gold purity is essential before making a purchase. The 20 carat gold purity percentage is 83.3%, meaning 83.3% of the metal is pure gold, while the remaining 16.7% consists of alloys like copper, silver, or zinc. This blend makes 20K gold strong enough for everyday wear while retaining a beautiful sheen. Under Indian Standard IS 1417:2016, 20K gold is officially recognised at a fineness of 833 (83.3%).

Why Choose 20K Gold?

• Stronger than 24K, ideal for jewellery you wear regularly.
• Maintains elegance and offers good resale value.
• Perfect for bridal wear, designer collections, and heirloom pieces.

Gold purity affects strength, colour, and value. Use this quick comparison to understand the purity percentages and most common applications for 24K, 22K, 20K, 18K, 14K, and 10K jewellery and bullion.

A quick note for Indian buyers: BIS permits hallmarking of only six caratages: 14K (585), 18K (750), 20K (833), 22K (916), 23K (958) and 24K (995). 10K is not a hallmarked grade in India, so treat any '10K hallmark' claim with caution.

Here are some common uses of 20-Carat gold:

Jewellery

Often used for bridal jewellery, designer collections, and intricate designs, where balance between durability and purity matters.

Investment

Coins and bars made of 20K gold are sought after by investors for their good purity and reasonable pricing.

Custom Creations

Artisans prefer 20K gold for bespoke and heritage pieces, adding gemstones for heirloom-quality items.

One clarification worth adding: BIS mandatory hallmarking applies to gold jewellery and artefacts, not to coins and bars. Investment-grade bullion is usually 24K (995/999) and can be hallmarked only by BIS-approved refineries or mints, so 20K is far more common in jewellery than in bullion.

Also Read: 22 Carat Gold Purity: Meaning, Uses and Value

Here are reliable methods to check what the wastage is in gold and verify authenticity.

Hallmark Certification – Official and Most Reliable

The easiest and safest method is to check the 20-carat gold hallmark. The hallmark includes the following:

• BIS Logo
• Purity Mark ('20K' or '833')
• Jeweller's Identification Mark
• Year Code
• Use the BIS Care app to scan and confirm hallmark details. Always buy from certified jewellers to avoid fraud.

The old four-mark hallmark above has been replaced. Since 1 July 2021, a hallmarked 20-carat gold piece carries just three marks:

• The BIS logo,
• The purity/fineness grade is now shown as '20K833'.
• A unique six-digit alphanumeric HUID (Hallmark Unique Identification) number.

The earlier jeweller's mark and year code are no longer stamped on the metal; those details are now stored digitally against the HUID.

You can confirm any piece in under a minute using the 'Verify HUID' feature in the BIS Care app, which pulls up the registered purity, jeweller and assaying centre. If a HUID returns no record, treat it as a red flag. As a paid option, any consumer can also get a hallmarked item independently tested for purity at a BIS-recognised Assaying & Hallmarking centre for a fire-assay charge of ₹200.

Nitric Acid Test – DIY with Caution

Apply nitric acid to a small scratch on the gold. No reaction indicates purity, while a colour change suggests impurities. However, this test is best done by professionals due to safety risks.

Magnet Test – Simple Home Check

Gold is non-magnetic. If your 20K gold jewellery sticks to a magnet, it likely contains non-gold metals. Use a strong neodymium magnet for accuracy.

Float Test – Quick and Easy

Place the jewellery in water. Pure gold sinks due to its high density. If it floats or moves unusually, it may be fake or gold-plated.

Density Test – Precise Method

Weigh the jewellery and measure its volume by water displacement. Use the formula: density = weight (grams) / water displacement (cm³). If the density is near 19.3 g/cm³, the gold is likely genuine.

Here are reliable methods to check what is wastage in gold and verify authenticity.

Hallmark Certification – Official and Most Reliable

The easiest and safest method is to check the 20 carat gold hallmark . The hallmark includes:

• BIS Logo
• Purity Mark ('20K' or '833')
• Jeweller's Identification Mark
• Year Code

Use the BIS Care app to scan and confirm hallmark details. Always buy from certified jewellers to avoid fraud.

Nitric Acid Test – DIY with Caution

Apply nitric acid to a small scratch on the gold. No reaction indicates purity, while color change suggests impurities. However, this test is best done by professionals due to safety risks.

Magnet Test – Simple Home Check

Gold is non-magnetic. If your 20K gold jewellery sticks to a magnet, it likely contains non-gold metals. Use a strong neodymium magnet for accuracy.

Float Test – Quick and Easy

Place the jewellery in water. Pure gold sinks due to its high density. If it floats or moves unusually, it may be fake or gold-plated.

Density Test – Precise Method

Weigh the jewellery and measure its volume by water displacement. Use the formula:Density = Weight (grams) / Water Displacement (cm³)If density is near 19.3 g/cm³, the gold is likely genuine.

Also Read: All You Need To Know About Gold Loan Per Gram Rate in India

When you see '833' stamped on gold, it means 833 gold means the piece is 83.3% pure – exactly 20 carat gold purity percentage . Understanding this helps you avoid scams and ensures you know what you are paying for. This is not an informal number: 833 is the official BIS fineness for 20K gold under IS 1417:2016, so a genuine 20K piece will read 20K833.

Here are some common gold scams and how you can avoid them:

Fake Hallmarks

Beware of fake 20 carat gold hallmark signs . Always verify hallmark details using the BIS Care app.

Gold-Plated Jewellery as Pure Gold

Gold-plated items look real but have only a thin layer of gold. The hallmark '833' helps distinguish genuine 20K gold from plated jewellery.

Manipulated Weights

Some jewellers use tampered scales to show more weight. Always cross-check weight with a calibrated digital scale.

Overpriced Making Charges

Compare making charges across multiple jewellers. Don’t pay the first price offered without negotiation.

The HUID system has made these scams much harder because each code is verifiable in real time against the BIS database; there is no stamp to simply copy. In districts where hallmarking is mandatory, selling non-hallmarked or falsely marked gold is also a punishable offence under the BIS Act, 2016, so insist on a hallmarked, HUID-bearing bill.

Genuine, hallmarked 20-carat gold is accepted as collateral by banks and NBFCs, and the rules changed meaningfully in 2025. The Reserve Bank of India (Lending Against Gold and Silver Collateral) Directions, 2025, were notified on 6 June 2025, with full compliance required from 1 April 2026; so they now govern every fresh gold loan.

The most significant change is the loan-to-value (LTV) ratio; that is, how much you can borrow against your gold's market value. The old flat 75% cap has been replaced by a tiered structure: up to 85% for loans up to ₹2.5 lakh, up to 80% for loans above ₹2.5 lakh and up to ₹5 lakh, and up to 75% for loans above ₹5 lakh.

In practice, if your 20-carat gold is valued at around ₹1,00,000, a small-ticket loan could fetch you up to ₹85,000 instead of the earlier ₹75,000. For loans up to ₹2.5 lakh, the RBI has also removed the need for detailed income or credit checks, which speeds up approval for households and small businesses.

Key borrower protections under the same directions:

• Your pledged gold must be returned within 7 working days of full repayment, with compensation of ₹5,000 per day of delay after that.
• Loans with bullet repayment (where principal and interest are cleared at the end) must be settled within 12 months.
• Broad borrower-level weight caps apply; gold ornaments up to about 1 kg and specified gold coins up to 50 g per borrower.
• You may be asked for proof of ownership (a purchase receipt or a simple self-declaration), and loan proceeds cannot be used to buy more gold.
• The lender must also issue a certificate stating purity (in carats), gross and net weight, and value your gold using a published reference price; a useful safeguard when you are pledging 20K jewellery.
• Be aware that interest rates, processing fees, and valuations can vary between lenders, and a higher LTV may result in a higher rate or a top-up call if gold prices fall. Compare offers and read the loan agreement before signing.

When you sell 20-carat gold, the amount you receive is based on the gold content, not the price you originally paid. Because 20K is 83.3% pure, most buyers calculate resale as roughly 83.3% of the prevailing 24K rate per gram, multiplied by the net weight of gold in the piece.

Two things reduce what you get back.

First, making charges and GST paid at purchase are generally not refunded on resale. Second, if you sell to a jeweller other than the original seller, they may re-test the purity and quote only on net gold weight, excluding the stones.

A hallmarked, HUID-bearing piece usually fetches a better and faster price because its purity is already certified and easy to verify.

A realistic expectation is that hallmarked 20K jewellery in good condition typically returns close to its current gold value, minus making charges and any stone deductions. Resale rates are set by the market, so no official government source was found that fixes a resale price for 20-carat gold; always compare quotes from two or three buyers before selling.

Here are some tips to check the purity of gold:

Use Precision Weighing Scales

Weigh the gold before and after to calculate how to calculate wastage in gold.

Cross-Verify Hallmarks

Always look for the official 20 carat gold hallmark sign.

Leverage Online Gold Purity Tools

Use a reliable gold wastage percentage calculator for quick estimation.

Consult Certified Jewellers

Avoid home tests like nitric acid unless done by professionals.

Knowing how to check the purity of 20-carat gold is essential for smart purchases. Rely on BIS hallmarks, density tests, and professional verification over DIY methods. Always buy from certified jewellers, and stay alert for fake hallmarks and manipulated scales. With the right knowledge, you ensure authenticity, durability, and good value for your 20K gold investment.

With the 2026 updates, the streamlined three-mark HUID hallmark and the RBI's borrower-friendly LTV tiers, you now have stronger tools to verify what you buy and to unlock its value when you need cash.

Also Read: 24-Carat Gold Purity Percentage Explained