Gold bars: cast, minted and good-delivery bars explained

A gold bar is the simplest way to own gold: a block of metal of known weight and purity, stamped by the refinery that made it. Everything else (the shape, the finish, the packaging) changes the price you pay far more than it changes what you own. This guide sorts out the families of bars, the sizes you will meet, and what to read on a bar before you buy it.

What every gold bar has in common

Whatever its size, a bar sold as investment gold carries the same core information, struck into the metal:

• the refiner’s mark, which tells you who guarantees the content;
• the weight, in troy ounces (1 oz = 31.1035 g) or in grams;
• the fineness, almost always 999.9 (“four nines”) for modern bars, sometimes 995 for large bars;
• a serial number on most bars above 10 g, which links the bar to the refiner’s records.

If one of these is missing, you are not looking at standard investment gold, and resale will be slower and cheaper.

Cast bars

Cast bars are made by pouring molten gold into a mould and letting it cool. The surface is slightly irregular, the edges are soft, and each bar looks a little different from the next. The stamp is added afterwards with a press or a hammer.

Casting is cheap to produce, which is why cast bars usually carry the lowest premium for a given weight. They are the standard format from 100 g upwards, and the only format for the large bars that banks and vaults trade between themselves.

Minted bars

Minted bars are cut from a rolled strip of gold to an exact size, then struck between dies like a coin. The result is flat, sharp-edged and often decorated on one side. Small minted bars are generally sealed in a tamper-evident card (an assay card) that repeats the weight, fineness and serial number.

The finishing work costs money, so minted bars carry a higher premium than cast bars of the same weight. Their advantage is practical: they are uniform, easy to store and easy for a buyer to check, which is why almost all bars under 100 g are minted.

Good-delivery bars: the wholesale standard

The bars behind the London gold market follow the rules of the London Bullion Market Association (LBMA). A good-delivery bar weighs between roughly 350 and 430 troy ounces (about 11 to 13 kg), has a minimum fineness of 995, and must come from a refiner on the LBMA’s accredited list.

Private buyers almost never handle these bars directly. They matter because the LBMA list is the reference used by dealers everywhere: a small bar from an accredited refiner is accepted almost anywhere, while a bar from an unknown maker will be tested, and discounted, before anyone buys it back.

The sizes that actually trade

The pattern is always the same: the smaller the bar, the more you pay per gram. A gram bar can cost several times its metal value in premium, while a kilobar is sold close to spot. Small bars make sense as gifts or to split a holding into pieces that are easy to sell one at a time, not as the cheapest way to buy gold.

Before you buy a gold bar

1. Check the refiner. Prefer bars from refiners on the LBMA good-delivery list. Their small bars are the easiest to resell.
2. Compare the premium, not the price. Divide the price by the fine weight and compare it with the spot price of the day. That gap is what the dealer charges you.
3. Ask for the buy-back price at the same time. The difference between what a dealer sells at and what it buys back at is the real cost of the round trip.
4. Keep the packaging. A minted bar still sealed in its original card resells faster than the same bar loose.

Our guides to buying gold bars, the main refiners and where to buy bullion go into each of these points.

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