Gold Purity and Fineness: Four Nines, 995.0 and What They Mean
Bullion purity is written as a decimal fineness. Jewellery purity is written in karats. They measure the same thing on different scales.
Fineness expresses gold content in parts per thousand. A bar marked 999.9 is 99.99 percent gold, usually called four nines. A karat mark expresses the same idea as a fraction of 24. Both answer one question: how much of this metal is actually gold.
Key takeaways
- Fineness is parts per thousand. 999.9 means 999.9 parts in 1,000 are gold.
- Karat is a fraction of 24. 18K means 18 parts in 24, or 75 percent.
- The Excise Tax Act uses 99.5 percent as the threshold for gold to count as a precious metal.
- The LBMA Good Delivery Rules set 995.0 as the minimum fineness for a Good Delivery bar.
- Higher purity is not better for jewellery, because pure gold is too soft to wear.
We do not sell bullion
Vanhess is a jewellery shop in Coquitlam, British Columbia. We sell solid gold jewellery. We do not sell, buy or broker bars, coins, ingots or wafers, and we are not a bullion dealer or a financial advisor. This page explains how bullion works so you can compare it fairly with jewellery. It is not a recommendation to buy anything.
The two scales side by side
| Fineness | Percentage | Karat equivalent | Where you see it |
|---|---|---|---|
| 999.99 | 99.999% | about 24K | Premium bullion coins |
| 999.9 | 99.99% | about 24K | Standard retail bullion bars and coins |
| 999 | 99.9% | 24K | Bullion, and some traditional jewellery |
| 995 | 99.5% | about 23.9K | LBMA Good Delivery minimum, and the Canadian tax threshold |
| 916 | 91.67% | 22K | South Asian and Middle Eastern jewellery |
| 750 | 75.00% | 18K | Fine jewellery |
| 585 | 58.33% | 14K | Everyday jewellery in North America |
| 375 | 37.50% | 9K | Lowest karat markable in Canada |
Why two numbers matter more than the rest
995.0 and 99.5 percent are effectively the same number, and they appear in two different places for two different reasons. The LBMA Good Delivery Rules use 995.0 as the minimum fineness for a Good Delivery bar. The Excise Tax Act uses 99.5 percent as the purity at which gold in bar, ingot, coin or wafer form becomes a precious metal for Canadian tax purposes.
Practically, almost all retail bullion sits well above that line at 999.9, so the threshold is rarely a live question when buying. It matters because it is the line jewellery can never cross.
Worth knowing
There is no such thing as pure 24K jewellery you can wear hard. Gold at 99.9 percent is soft enough to deform under a fingernail, which is why every practical jewellery alloy sits well below the bullion purity range.
Frequently Asked Questions
What does 999.9 gold mean?
It means 999.9 parts in every 1,000 are pure gold, or 99.99 percent, commonly called four nines. It is the standard purity for most retail gold bullion bars and coins.
Is 24K gold 100 percent pure?
In practice no. 24K is the karat notation for pure gold, but refined gold is expressed as 999, 999.9 or 999.99 fine, because a small fraction of other elements always remains. The Royal Canadian Mint produces a 99.999 percent coin, which it describes as the highest purity standard of refined gold.
What is the minimum purity for gold to avoid GST in Canada?
Subsection 123(1) of the Excise Tax Act defines a precious metal as a bar, ingot, coin or wafer of gold, silver or platinum refined to at least 99.5 percent purity for gold and platinum. Both the form and the purity conditions must be met.