KDM vs 916 Gold vs Hallmark Gold: Key Differences Explained

KDM, 916, and hallmark gold are not the same thing, and confusing them can cost you money. KDM refers to a cadmium-based soldering technique that has since been discontinued in India; 916 denotes 91.6% gold purity (22 karat); and hallmark is a BIS certification confirming that a piece meets declared purity standards. A single jewellery item can be both 916 and hallmarked. Understanding the difference between KDM and 916 gold, and what hallmarking actually certifies, is essential before making any purchase.

This guide breaks down every distinction clearly, so you can buy gold with full confidence.

Hallmark Gold refers to gold jewellery or bullion certified by an authorised body for purity and fineness. In India, the Bureau of Indian Standards (BIS) is responsible for hallmarking gold under the BIS Hallmarking Scheme. This certification ensures that the gold meets the prescribed purity standards, protecting consumers from fraud.

The jewellery is checked again before being returned to the jeweller for sale.Since June 2021, hallmarking has been mandatory in India for gold jewellery and artefacts, ensuring transparency and trust in gold purchases.

A BIS hallmark stamp on a piece of jewellery includes four key components:

• The BIS logo (a triangle with 'BIS' inscribed inside)
• The mark that says how pure or fine the metal is, like "916" for 22K gold.
• The mark used to identify the Assaying and Hallmarking Center
• A six-digit alphanumeric Hallmark Unique Identification (HUID) number

The HUID is a significant addition introduced by BIS in 2021. A unique HUID code is given to each piece of hallmarked jewelry. This code can be checked using the BIS Care app or the official BIS website. This way, buyers can check the item's authenticity on their own, instead of just relying on the jeweler.

It's important to remember that hallmarking is not a purity grade but a way to prove that something is real. BIS stamps gold with different karat amounts, such as 14K (585), 18K (750), 22K (916), and 24K (999). There is a mark on a piece that lets you know it has been checked, and the purity number inside the mark tells you what level of checking went on.

KDM is short for "Kadmium," which is the German word for cadmium. It refers to a way of soldering that was commonly used in Indian jewelry making in the past.

A cadmium-based solder alloy, which was usually a mix of 92% gold and 8% cadmium, was used by jewelers in the KDM process to connect gold pieces while making jewelry. This method was appealing because it was useful: cadmium lowers the melting point of the solder, which makes it easier to join small pieces of gold together without damaging the metal around them. This made it possible for craftsmen to make complicated designs that would have been hard to make any other way.

KDM gold is no longer preferred or manufactured in India due to health hazards. Cadmium is a toxic heavy metal classified as a carcinogen. KDM gold is no longer preferred due to health hazards. Cadmium is toxic and can cause respiratory and skin-related issues in artisans handling it. As a result, the BIS banned cadmium soldering, replacing it with hallmarked gold jewelry.

Since then, the industry has switched to cadmium-free alternatives, such as copper-zinc and silver-based soldering alloys, which are just as easy to work with but are safer. These alternatives have largely replicated the ease that made cadmium popular, without the associated health risks.

New KDM gold jewellery is no longer manufactured or sold in India. Existing KDM pieces can still be exchanged or sold at most jewellers, though they will not carry a current BIS hallmark.

The number 916 gold means 22-karat gold, which is 91.6% pure gold. The number '916' is a per-mille (parts per thousand) expression of purity: the alloy contains 916 parts of pure gold per 1,000 parts total, which works out to 91.6 grams of pure gold per 100 grams of the alloy.

The remaining 8.4% is typically made up of alloyed metals such as copper, silver, or zinc. These additions serve a functional purpose: pure gold (24K) is quite soft, which makes it unsuitable for daily-wear jewellery that needs to withstand regular handling. The alloyed metals improve hardness and durability without significantly reducing the gold content.

A lot of people in India like to wear jewelry made of 916 gold. It is a good mix of high purity and practical durability. Jewelry made from 916 gold keeps its shape well, doesn't scratch as easily as 24K gold, and keeps the warm color and shine of high-purity gold.

Also, it's important to know that 916 gold can have a BIS mark on it, which makes it "BIS 916 hallmarked gold." A common and important difference is that "916" refers to the purity and "hallmark" refers to the certification. There is no difference between these two terms; the same piece can be both 916 and hallmarked.

Here is how different purity grades compare:

One of the most important things to understand is that hallmark, 916, and KDM are not three parallel types of gold. They are three different descriptors that operate on different axes:

• Hallmark is a certification issued by BIS confirming that the gold meets declared purity standards.
• 916 is a purity grade, indicating 91.6% gold content (22 karat).
• KDM is a method of making things that no longer exists. It joined gold pieces together with cadmium solder.

A piece of jewellery can be 916 and hallmarked at the same time. As a matter of fact, most 22K gold jewelry sold in India today is marked "BIS 916." KDM, on the other hand, is neither a purity grade nor a certification. It is just an old way of soldering that has been replaced.

The table below summarises the key distinctions:

The phase-out of KDM gold in India was driven by health and safety concerns, not purity. The fact that KDM jewelry usually has about 92% gold in it wasn't the problem. Lead, which was used in the solder, was the problem.

Cadmium is classified as a Group 1 carcinogen by the International Agency for Research on Cancer. Jewellers who worked with cadmium solder on a regular basis were exposed to cadmium fumes during soldering, which posed serious risks of respiratory disease, kidney damage, and other long-term health conditions. There were also concerns about the potential for cadmium to leach from the solder into contact with the wearer's skin over time.

As part of its IS 1417 standard, which sets safety and purity standards for gold jewelry, BIS banned the use of cadmium in soldering. The order meant that India could no longer make any new KDM gold jewelry.

The industry responded by adopting cadmium-free soldering alloys. Copper-zinc and silver-based alternatives are now widely used in gold jewellery fabrication. These alloys offer a manageable melting point that allows jewellers to continue producing intricate designs, without the toxicity associated with cadmium.

Note: While KDM gold is no longer manufactured, existing KDM pieces can still be exchanged or resold at most jewellers. However, they will not carry a current BIS hallmark, which may affect their resale valuation.

Verifying a hallmark before purchasing gold jewellery is a practical step that protects your investment. Here is a step-by-step guide:

• Step 1: Look for the BIS logo. The BIS hallmark includes a triangular logo with 'BIS' inscribed inside. It should be clearly and precisely engraved on the jewellery. If the mark appears blurry, uneven, or faint, treat the situation as a warning sign.
• Step 2: Check the purity fineness mark. Find the three-digit number that tells you how pure the gold is. For example, "916" means 22K, "750" means 18K, and "585" means 14K. This number lets you know what karat level the jewelry is certified at.
• Step 3: Locate the six-digit HUID code. Introduced by BIS in 2021, the Hallmark Unique Identification (HUID) is a six-character alphanumeric code unique to each piece of jewellery. It is stamped alongside the BIS logo and purity mark.
• Step 4: Verify the HUID on the BIS Care app. Download the BIS Care app (available on Android and iOS) or visit the official BIS website. Enter the HUID code to confirm that the piece is registered and that the details match what the jeweller has told you.
• Step 5: Use a magnifying glass if needed. Hallmark stamps are small. A genuine BIS hallmark will be precise and legible under magnification. A poorly stamped or incomplete mark may indicate that the jewellery has not been certified.

Consumer Tip: If you are unable to verify the HUID on a piece of jewellery being sold to you, you can report the jeweller to BIS. Hallmarking is mandatory for gold jewellery sold in India, and non-compliance is a reportable offence.

Gold purity directly determines the price per gram of jewellery. The higher the purity, the greater the gold content, and the higher the price:

• 24K gold (999 fineness) is the purest form and commands the highest per-gram price. It is typically used for coins, bars, and digital gold rather than wearable jewellery.
• 22K gold (916 fineness) is priced slightly lower but remains the standard for jewellery purchases in India.
• 18K gold (750 fineness) carries a lower price per gram, making it common for designer and studded jewellery.

Hallmarked gold typically commands a better resale price than non-hallmarked gold. When you take hallmarked jewelry to a jeweler to be resold or traded in, the BIS certification, especially the HUID, lets them check the purity right away, without having to do any other tests. For the buyer, this lowers their risk and makes the deal easier to understand.

KDM gold, lacking a current BIS hallmark, may be assessed at a lower rate when presented for resale. Jewellers may factor in additional testing costs or apply a discount due to the uncertainty around the piece's exact composition. The process of reselling KDM gold may take longer and yield a lower price.

Practical Tip: Always ask for the hallmark certificate or confirm the HUID on the BIS Care app before completing any gold purchase. Gold is a long-term asset, and verifying purity at the point of purchase protects its investment value over time.

The right choice depends on your purpose:

• For jewellery buyers: BIS-hallmarked 916 (22K) gold is the best option. It offers a high purity level with sufficient durability for everyday wear, and it is the most widely accepted type for resale across India. Always buy from a BIS-certified jeweller and verify the HUID on the BIS Care app before completing your purchase.
• For investors: The purest gold is 24K coins, bars, or digital gold. Sovereign Gold Bonds (SGBs) issued by the Government of India are another route worth considering for long-term investment, as they provide returns linked to gold prices without the need for physical storage.
• For those with existing KDM jewellery: No new KDM gold is being manufactured or sold. If you currently own KDM pieces, most jewellers will accept them for exchange or buyback, though the price may be assessed differently from BIS-hallmarked jewellery. It is worth getting the piece independently tested for purity before agreeing to an exchange rate.

What to Ask Your Jeweller Before Buying: Request the HUID of the piece before purchase. Ask for a purchase receipt that includes the HUID, purity mark, and weight. Confirm that the jeweller is BIS-certified. If buying 22K jewellery, check that the '916' fineness mark appears alongside the BIS logo. If a mark cannot be verified on the BIS Care app, do not proceed with the purchase.

Lenders prefer hallmarked gold or 916 gold (22-karat) when processing a gold loan application, since these have verified purity that can be confirmed quickly. Here are a few points to keep in mind when approaching a gold loan:

• Loan-to-Value (LTV): The Reserve Bank of India (RBI) allows lenders to offer loans up to 75% of the gold's market value. Choosing lenders that offer the maximum LTV helps you access the highest possible loan amount against your gold.
• Interest Rates and Fees: Gold loan interest rates typically range between 7% and 20% per annum, depending on the lender and the gold's purity. Always check for processing fees, valuation charges, and any foreclosure penalties before signing.
• Loan Tenure: Gold loans generally carry tenures of 3 to 36 months. A shorter tenure reduces the total interest paid over the loan's life.
• Repayment Flexibility: Some lenders offer monthly EMI repayments, while others allow bullet repayments, where monthly interest is paid and the principal is repaid at maturity. Choose the method that fits your cash flow.
• Gold Security: Confirm that the lender stores your gold in a secure, insured vault. Reputable banks and NBFCs maintain dedicated storage with insurance cover against theft or damage.

KDM gold may be accepted for a gold loan, but lenders may apply additional testing or offer a reduced LTV due to the absence of BIS certification. BIS-hallmarked gold, particularly 916, gives you the clearest pathway to securing the full loan value.

When buying gold, understanding these terms is essential for making a wise investment. Hallmarked gold ensures authenticity and purity, offering the safest and most reliable choice. 916 gold (22K) balances durability and purity, making it ideal for jewellery. KDM gold, once popular for intricate designs, has been phased out due to health risks. If you purchase gold for long-term value or a loan, opt for BIS-hallmarked physical gold for guaranteed purity. You can also find the same quality and purity in digital gold, which offers a convenient and secure way to invest without the hassle of storage or purity concerns.