Back to all resources
Karat Meaning Explained: 22K, 24K Gold, Gold Purity, and Difference with Carat
By Jupiter Team · · 8 min read
Quick take: If you want the purest gold, choose 24K. For daily wear jewelry, 22K is ideal. A 1 carat diamond weighs 0.2 grams. Check the BIS hallmark to confirm the karat of your gold jewelry.
What is Karat?
Karat (written as K) is a unit that measures the purity of gold on a scale of 24 parts. Pure gold is 24K, meaning all 24 parts are gold. Lower karats indicate gold mixed with other metals such as silver, copper, nickel, or zinc to improve hardness and adjust color.
'Karat in some of the Indian Languages
How to explain ‘Karat’ to kids?
Think of gold like chocolate. 24K is pure chocolate. 22K has a little bit of nuts mixed in, so it is stronger for everyday bites. Karat tells you how pure the chocolate is. Diamonds use carat, which is about weight. A 1 carat diamond weighs 0.2 grams, just like a tiny chocolate piece weighs a bit.
History of the unit Karat and Carat: Etymology explained
Where do the words karat and carat come from? The terms trace back to the carob seed, once used as a reference weight for gems. Over time, usage split into two related ideas. Karat denotes the purity of gold. Carat denotes the weight of gemstones. This means that the same sounding word can refer to different concepts depending on context. In other words, K aligns with gold purity and ct aligns with gem weight.
Quick side-story about ‘24 Karat’
Why “24 parts” for gold purity?
Historical origin
The Roman solidus gold coin was defined as 24 siliquae in weight. Over time, each siliqua was treated as a carat, so a perfectly pure coin was 24 carats. Purity in jewelry alloys then got expressed as ‘parts out of 24’
The word carat/karat itself comes from Greek keration via Arabic qīrāṭ, a seed-based weight that later tied into coin and gold standards.
What makes 24 practical?
- It is highly divisible. You can split 24 by 2, 3, 4, 6, 8, and 12, which made old-world assaying and mint measurement easier. This convenience helped the 24-part convention continue in workshops and trade.
To make it easier to understand
- 24K equals “24 parts out of 24 are gold,” so effectively pure for trade.
- 22K equals “22 parts gold and 2 parts other metals.”
- The 24-part scale is a direct legacy of late Roman and Byzantine coinage, carried forward into modern hallmarking language.
In other words
- We do not use 24 because it is a nicer number than 100. We use it because historical coin standards fixed the benchmark at 24 units, and jewelers kept that convention.
Difference between Karat and Carat
- Karat (K) measures purity of gold. Example: 22K, 18K, 14K.
- Carat (ct) measures the weight of gemstones like diamonds. Example: 1 ct equals 0.2 grams.
What makes this distinction important for buyers? When choosing jewelry, you might select 22K for durability while also asking for a 1 carat diamond. The first figure is purity. The second is weight. Similar to clothing size versus fabric quality, both matter but describe different properties.
Karat vs ct vs K: understanding the terminology
- K is the standard symbol for gold purity, for example 24K.
- ct is the standard symbol for gemstone weight, for example a 1 ct diamond.
- carat is the spelled out unit for gemstone weight.
- karat is the spelled out unit for gold purity.
Experts recommend writing K for gold and ct for diamonds to avoid confusion in invoices and appraisals. So C for D i.e. Carat for Diamond and K for G, Karat for Gold. Easy to understand now?
Dictionary meaning
Karat is a unit to measure the purity of gold. 24K is pure gold. Carat in diamonds measures weight, not purity. 1 carat = 0.2 grams.
Karat in gold
Gold is soft in its pure form. Jewelers alloy gold with copper, silver, nickel, or zinc to improve hardness and adjust color. Depending on your need, different karats fit different use cases.
22K, 24K, 18K, and other karats explained
How does purity relate to durability? Unlike 24K, which is very soft, 22K and 18K have more alloying metals, so they resist scratches better. This means that for rings and bangles that face daily friction, 22K or 18K is often more practical.
How to check karat of gold at home
If you are looking for quick checks, try these methods. Depending on your situation, some are better than others.
- Look for the BIS hallmark. Check for a BIS mark and fineness number such as 916 for 22K. Modern hallmarking includes a unique HUID code that a jeweler can verify.
- Touchstone and acid test kit. A small scratch on a touchstone reacts with acid solutions. This is a traditional method and should be done carefully.
- Density check. 24K gold has a higher density. A rough water displacement test can indicate purity, although it is not precise for jewelry with stones.
- Professional testing. XRF machines at certified jewelers provide non destructive purity readings.
For example, if a necklace is stamped 22K 916 and carries a BIS hallmark, that is a strong indicator of authenticity. It is recommended to check the quality of your jewellery with a trusted jeweler when in doubt.
Hallmarking and its importance
BIS hallmarking in India certifies the purity of gold jewelry. Why do experts prefer hallmarking? Because it protects buyers against under karating and ensures fair valuation during resale or exchange. Hallmarking indicates fineness, jeweler registration, and the center that performed the test. This gives traceability and improves consumer confidence.
Karat in diamonds
Diamonds do not use karat. They use carat (ct) for weight. Carat impacts price because heavier stones are rarer. However, weight is not the only quality driver.
What is 1 carat diamond?
A 1 carat diamond weighs 0.2 grams. If you prefer a rule of thumb, think of 5 carats as 1 gram. What makes this important for buyers? The same carat weight can look larger or smaller based on cut proportions and shape.
Carat weight vs quality
How does carat relate to quality? Carat is weight. Quality depends on the 4Cs:
- Cut influences brilliance and face up size.
- Color ranges from colorless to tinted.
- Clarity measures internal and external flaws.
- Carat is the weight. Bigger is not always better if cut, color, or clarity are compromised.
Depending on your budget, optimizing cut first, then balancing color and clarity, often gives better sparkle than chasing carat weight alone.
Diamond carat weight reference table
Common questions about karat
Which is better, 22K or 24K gold?
Why do many buyers prefer 22K for wearable jewelry? 24K is purer, but 22K is more durable because of alloying metals. If you are buying coins or bars for investment, 24K makes sense. If you are buying rings, bangles, or chains for daily use, 22K is practical.
Is 22K gold magnetic?
Pure gold is not magnetic. Most common 22K alloys are also non magnetic. If jewelry shows magnetic attraction, it could be due to a clasp component, contamination, or non gold parts. This is why magnet tests alone are not reliable for purity verification.
What is 916 gold?
916 gold is another way of writing 91.6 percent purity, which is 22K. When you see 916 on BIS hallmarked jewelry, it indicates the fineness level associated with 22K gold.
Comparison and guides: 22K vs 24K gold
How does 22K compare with 24K in real life?
- Purity. 24K is 99.9 percent pure. 22K is 91.6 percent.
- Durability. 22K is harder and resists scratches better than 24K.
- Use case. 24K for investment. 22K for regular jewelry.
- Resale. Both hold value, but ease of resale depends on local market and hallmarking.
Research shows that daily wear jewelry benefits from stronger alloys. Similar to how pure silver scratches easily compared with sterling silver, pure gold marks faster than 22K or 18K variants.
Types of Gold and variations you will see
- 24K. Highest purity, distinct yellow hue, softer metal.
- 22K. Most popular for Indian jewelry, balanced purity and strength.
- 18K. Preferred in many designer settings, especially with diamonds.
- 14K. Common in Western markets for everyday wear.
- Diamond carat examples. 0.5 ct, 1 ct, 2 ct across earrings, rings, and pendants.
Karat comparison table for gold
How to check karat: step by step guide
- Inspect the stamp. Look for 24K, 22K, 18K, or fineness numbers like 999, 916, 750.
- Confirm BIS hallmark. BIS logo, fineness mark, and HUID provide traceability.
- Ask for a bill and certificate. Always keep the invoice with karat and weight details.
- Professional verification. Use an XRF test at a reputed jeweler for a quick, non destructive check.
If you are looking for the safest path, buy only BIS hallmarked jewelry from registered jewelers and keep the HUID details in your records.
Diamond carat vs appearance
Two diamonds can both weigh 1 ct but look different sizes. Why does this happen? A well cut stone spreads weight toward diameter, creating better face up size and sparkle. Depending on your preference for size or sparkle, you might choose a 0.9 ct ideal cut over a 1 ct deep cut to stay on budget without losing visual impact.
FAQs
What is 22K gold?
22K gold is 91.6 percent pure gold alloyed with other metals for strength. It is popular for traditional Indian jewelry.
How to check karat of gold at home?
Use a hallmark check, a touchstone acid kit, or visit a jeweler for XRF testing. For delicate or studded items, professional checks are best.
What is 916 gold?
916 refers to 91.6 percent purity, which equals 22K.
Which is better, 22K or 24K gold?
24K is purer. 22K is stronger. For everyday jewelry, 22K is typically better. For coins and bars, 24K is preferred.
Does 1 carat diamond equal 1 gram?
No. 1 carat equals 0.2 grams.
In this article