Gold Purity Explained: 24k vs 22k and What 999.9 Really Means

Here's a question that trips up almost every first-time gold buyer: does a 22-carat Krugerrand contain less gold than a 24-carat Maple Leaf? Both are sold as "one ounce" coins, one is 91.67% pure and the other is 99.99% — so surely the purer one has more metal?

No. They contain exactly the same amount of gold. Here's why, and everything else the purity numbers actually tell you.

The karat system in one line

A karat is a twenty-fourth. 24 karat means 24 parts out of 24 — pure gold. Each karat is 1/24, or 4.1667%.

Millesimal fineness says the same thing in parts per thousand, which is why you see "999.9" stamped on bars rather than "24k".

Karat	Gold content	Fineness	Typical use
24k	99.9%+	999 / 999.9	Bullion coins and bars
22k	91.67%	916	Krugerrand, Eagle, Sovereign
18k	75.0%	750	Fine jewellery
14k	58.33%	585	US mass-market jewellery
9k	37.5%	375	UK budget jewellery

The bit that confuses everyone

Purity describes the alloy, not the gold content. A one-ounce bullion coin contains one troy ounce of pure gold whatever its carat — the alloyed ones are simply heavier overall.

A 1 oz Krugerrand has a gross weight of 33.93 g. Of that, 31.1035 g is fine gold and roughly 2.83 g is copper. It's bigger and heavier than a 1 oz Maple Leaf, not lighter on metal. You are buying the same ounce either way.

Where this genuinely matters is scrap and jewellery. An 18k chain really does contain 25% less gold than a 24k one of the same weight. With sovereign bullion coins, the stated ounce is always fine gold.

Which coins are which

24 carat (.999 / .9999): Canadian Maple Leaf, Austrian Philharmonic, American Buffalo, Australian Kangaroo, Britannia from 2013, and the Chinese Panda at .999.

22 carat (.9167): Krugerrand, American Gold Eagle, British Sovereign, and Britannias struck before 2013.

Do the extra nines matter?

The difference between .999 and .9999 is 0.09% of the metal — about 0.028 g on a one-ounce coin. That's less than a typical dealer spread. Economically it's noise.

What the extra nines do change:

• Hardness. Purer gold is softer. A .9999 coin marks, dings and fingerprints more easily than .999, and far more easily than 22k.
• Regional preference. Some Asian markets — notably China, Hong Kong and parts of India — favour .9999 and will pay slightly more. Western dealers generally won't pay extra per gram of fine gold.
• Novelty pricing. The Royal Canadian Mint's .99999 "five nines" Maple Leaf editions cost more for rarity, not gold content.

If a seller is charging you a meaningful premium purely for an extra nine, you're paying for marketing.

Why 22 carat exists at all

Durability. Pure gold is genuinely soft — Mohs hardness around 2.5. The Krugerrand was designed in 1967 as a circulating-style coin, and the copper alloy makes it hard enough to survive handling, stacking and shipping. It also gives it that distinctive rose tint.

In practice: 22k coins hold condition better in bulk storage and rough handling. 24k coins want capsules and tubes. If you plan to actually look at and handle your gold, that's a real consideration — and it feeds directly into how you store it.

The purity thresholds that carry legal weight

Two numbers decide whether metal counts as "investment gold":

• Bars: fineness of at least 995, in a weight accepted by the bullion markets.
• Coins: fineness of at least 900, minted after 1800, legal tender in their country of origin, and normally sold at no more than 180% of their gold value.

Meet those and the purchase is VAT-free in the UK and EU. Note that the coin threshold is 900, not 995 — which is exactly why 22-carat Krugerrands and Sovereigns (both .9167) qualify comfortably.

Separately, LBMA Good Delivery wholesale bars require a minimum of 995.0 fineness. That's a different standard for a different purpose, and it doesn't apply to retail products — we untangle that in what LBMA Good Delivery actually means.

Hallmarks vs assay marks

Hallmarking is a jewellery regime — sponsor's mark, fineness, assay office, date letter. Investment bullion generally isn't hallmarked in that sense, and legal-tender coins sit outside the system entirely.

What you should see on a proper bullion bar is the refiner's mark, the weight, the fineness to four figures (e.g. 999.9), a unique serial number and the assayer's mark, usually with a matching assay card. That's your verification chain — see how to tell if a gold bar is real.

So what should you actually buy?

Purity is one of the least important factors in a bullion decision. Premium, tax treatment and liquidity matter far more. A 22k Krugerrand and a 24k Maple hold identical gold; choose on cost, on whether you value hardness over purity, and — if you're a UK taxpayer — on whether the coin is CGT-exempt.

Browse the full gold range at Bitgolder, all at 99.9% purity or finer from sovereign mints and LBMA-accredited refiners, payable in Bitcoin, Monero, stablecoins and 30+ coins at a transparent premium over live spot. Still choosing a format? Read coins vs bars.

Frequently asked questions

What does 999.9 mean on gold?

It is millesimal fineness — 999.9 parts of gold per 1,000 parts of metal, or 99.99% pure. Also written .9999 or four nines, it is the standard for modern 24 carat bullion coins like the Maple Leaf and Philharmonic.

Does a 22k gold coin contain less gold?

No. A 1 oz Krugerrand contains a full troy ounce (31.1035 g) of pure gold. It simply weighs more in total — 33.93 g gross — because around 2.83 g of copper is alloyed in. Purity describes the alloy, not the gold content.

Is 24k better than 22k for investment?

Not in gold content — a 1 oz coin of either purity holds one full troy ounce. 24k suits buyers who want maximum purity or sell into Asian markets; 22k resists scratches and dings. Choose on premium and liquidity, not the purity number.

Is .9999 gold worth more than .999?

Materially, no. The extra nine adds 0.09% more gold — about 0.028 g on a one-ounce coin, less than a typical dealer spread. Price differences come from brand and regional preference, not gold content.

What is the purest gold coin?

The Royal Canadian Mint's .99999 five-nines Gold Maple Leaf special editions, first struck in 2007. Among standard bullion, .9999 is the practical ceiling — Maple Leaf, Philharmonic, Buffalo, Kangaroo and post-2013 Britannia.

What purity qualifies as investment gold?

For UK and EU VAT exemption, bars need at least 995 fineness in a bullion-market weight; coins need at least 900 fineness, minting after 1800, legal-tender status, and a price no more than 180% of their gold value. That is why 22 carat Krugerrands and Sovereigns qualify.

Why is some gold 22 carat instead of pure?

Durability. Pure gold is soft, around 2.5 on the Mohs scale, and marks easily. Alloying with copper makes coins like the Krugerrand hard enough to survive handling, stacking and shipping — and gives them their rose tint.