Classification of gold bars
Gold bars are classified into two types, dependent on their method of manufacture: cast and minted.
A gold bar is broadly defined as a cast or minted gold item, regardless of shape, which is made by a recognized bar manufacturer. It is normally issued at a low premium above the prevailing value of its fine gold content.
The markings on gold bars are mainly functional and record the name of the manufacturer or issuer where required, the bar’s weight and gold purity, and a serial number.
However, it can be noted that the characteristics of gold bars manufactured worldwide can vary with many widely traded bars having their own distinctive features.
For example:
- London Good Delivery “400 oz” bars have variable weights and purities, and the weight is not normally recorded on the bar.
- The minimum or specified gold purity of bars, accepted as “good delivery” by leading associations and exchanges, can range from 99% to 99.99%.
- Most minted bars manufactured worldwide include a design or motif on the reverse side as a standard feature.
- Whereas most cast bars carry a serial number, like gold coins, most small minted bars manufactured worldwide do not.
- Many cast gold bars have few or no markings and variable weights and purities when produced for jewellery, industrial and other purposes.
The bulk of gold bars manufactured worldwide is purchased by jewellers, manufacturers and other industries. All cast and minted gold bars can be used by both fabricators and investors when issued or made available at a low premium above the prevailing value of their gold content.
Cast bars
Cast gold bars are normally produced directly from gold that has been melted.
However, the way in which melted gold is used in their manufacture can vary.
The traditional method is to cast (i.e. pour) gold, which has been melted in a crucible, into a mould with appropriate dimensions.
A modern method, now widely used to manufacture smaller cast bars, is to place a measured weight of gold granules or cut pieces of gold into a mould with the appropriate dimensions and then melt it in a furnace.
Another modern method used to create a cast bar that is long and flat, especially for the manufacture of minted bars, is to pass melted gold through a die, which has a specified width and thickness and has been clamped between cooling blocks in a continuous casting process.
Markings, if required, are usually applied manually or by a press.
When manufactured in an open mould, most cast gold bars are “inclined” (i.e. tapered) in shape to facilitate their removal from the mould. Consequently, the dimensions (length and width) of the top and base surface areas are not normally the same. While the top surface is usually smooth, the base and sides tend to be relatively rough.
Although cast bars are normally rectangular (broad or narrow, flat or inclined), some refiners also manufacture them in other shapes (e.g. rod, round, square).
Minted bars
Minted gold bars are normally cut from a cast bar that has been rolled to a uniform thickness. The cutting is usually done with a die to create blanks that have the required dimensions and weight.
All the surfaces (top, base and sides) are smooth and even. Markings are normally applied by a minting press.
Although most minted bars are rectangular, they are also manufactured in a variety of other shapes (e.g. round, square, oval).
Minted “pendant” bars, which incorporate a hook or hanger so they can be worn, are also manufactured.
Terminology: minted gold bars are also referred to as ingots (gold ingots), and in some countries as wafers, minted products or “coins”, when the shape is round.
Further definitions for gold bars
The following are broad definitions and classifications used by The Industry Collection of Gold Bars Worldwide.
Unwrought bars
The Industry Collection classifies low purity cast gold bars (i.e. newly- mined doré bars and bars made from melted down scrap), and refined cast gold bars used for fabrication or investment purposes, as unwrought bars.
It also classifies minted gold bars for fabrication or investment purposes as unwrought bars when they are manufactured by a recognized bar manufacturer, include official markings and are known to have been issued at a low premium above the prevailing value of their fine gold content.
However, it can be noted that while some countries classify minted gold bars as “unwrought”, others classify them under some other category, notably as “other semi-manufactured forms” or as “other articles of precious metal”.
Investment bars
The Industry Collection also classifies a cast or minted bar as an investment bar when it is known to have been issued by a recognized bar manufacturer or issuer at a low premium above the prevailing value of its fine gold content.
Ornamental bars
Within the Industry Collection, this classification applies to gold bars that are issued at a fixed price or at a high premium above the value of their fine gold content. This would include the limited edition of proof “Fine Art” bars from Singapore, and “model bars” from South Korea.
Note on pendant bars
The Industry Collection normally classifies minted pendant gold bars, i.e. those that incorporate a hook or hanger so they can also be worn, as investment bars. This classification is applied when the gold bars are issued by a recognized bar manufacturer or issuer, include the same official markings as standard minted bars, and are issued at a low premium above the prevailing value of their fine gold content.
Source: Gold Bars Worldwide