The short answer
Gold coins are made either of nearly pure gold or of gold mixed with other metals. Modern investment coins such as the Canadian Gold Maple Leaf, the Austrian Vienna Philharmonic and the American Gold Buffalo are struck in very high purity gold, typically .9999 fine or close to it. Other well-known coins, including the American Gold Eagle, the South African Krugerrand and the British Sovereign, are 22 karat (91.67% gold), with copper and often silver making up the rest.
Which one you are holding matters for value, for handling and for testing whether a coin is real.
Gold purity: karats and fineness
Purity is described in two ways.
- Karats divide the metal into 24 parts. 24 karat is pure gold, 22 karat is 22 parts gold in 24 (91.67%), and 18 karat is 75%.
- Fineness gives the gold content in parts per thousand. A coin marked .9999 is 99.99% gold, and a 22 karat coin is about .9167 fine.
Coins are rarely labelled in karats. Look for the fineness, the gold content in ounces or grams, or both. Many bullion coins state something like “1 oz fine gold” on the coin itself.
Nearly pure gold coins
Coins in the .999 to .9999 range are often called “pure gold” coins. Examples include the Gold Maple Leaf, the Vienna Philharmonic, the American Gold Buffalo and, in its modern form, the Britannia. Some earlier releases of a coin may have been struck to a different standard, so check the specific year.
Pure gold is very soft. These coins mark and scratch easily, which is why they are usually kept in capsules, tubes or sealed packaging. Their value is tied closely to their gold weight, and their stated weight is their gold weight.
22 karat alloy coins
Many long-running coins use the 22 karat standard. Typical examples:
- American Gold Eagle (from 1986): 22 karat, containing one troy ounce of gold in a one-ounce coin that weighs a little more than an ounce overall because of the alloy.
- Krugerrand (from 1967): also 22 karat, with copper as the alloying metal.
- British Sovereign: 22 karat, about 7.98 g in total weight. See our guide to identifying gold sovereign coins.
Because the alloy adds weight, the total weight of these coins is higher than the amount of gold they contain.
Why other metals are added
Gold alone wears quickly. Adding copper, silver or other metals makes a coin harder, so it resists scratches, dents and wear. Copper tends to give the coin a warmer, slightly reddish tone, while more silver gives a paler yellow. Historically this mattered for coins that were meant to circulate and be handled daily.
What bullion means
Bullion is precious metal valued mainly by its weight and purity rather than by rarity or age. A bullion coin is a coin sold close to the value of its metal, often with a small premium over the spot price. A numismatic coin, by contrast, is valued by rarity, condition and collector demand, and may be worth far more or less than its gold content.
This is also why composition matters for collectors. A common-date sovereign may trade near its gold value, while a scarce date or mint can carry a significant premium.
Historic gold coins
Older gold coins follow different standards. United States gold coins made from 1837 until the early 1930s were generally 90% gold and 10% copper. Ancient and medieval coins varied widely, and some contained a good deal of silver in their natural gold. For US coins of other metals, see our breakdown of US coin metal composition.
Gold content versus total weight
When comparing coins, separate two figures:
- Total weight, which is what you would measure on a scale.
- Actual gold weight (AGW), which is the total weight multiplied by fineness.
For a Sovereign, multiplying roughly 7.98 g by .9167 gives about 7.32 g of gold, which is a little under a quarter of a troy ounce. Dealers use this calculation to work out melt value.
Buying gold coins and checking they are genuine
Gold coins are normally bought from established coin dealers, bullion dealers and mints. Some banks may sell or buy coins, but practice varies by bank and country, so it is worth asking in advance rather than assuming. Reputable sellers will state the coin, year, weight and purity, and will usually accept returns on faulty items.
Before relying on a purchase, compare the coin’s weight and dimensions to published specifications. A magnet check can rule out some fakes, but it cannot prove a coin is genuine.
FAQ
Are coins really made from gold? Yes, some are. Many modern coins in circulation are base metal, but bullion and some historical coins are gold or gold alloy.
What is the best gold coin to collect for investment? There is no single answer. It depends on your budget, goals and whether you want bullion value or collector appeal. Widely recognised, well-documented coins are generally easier to buy and sell, but this is general information and not financial advice.
Is 22 karat gold real gold? Yes. It is 91.67% gold, with the rest being other metals added for durability.