Parameters of coins and bars



One troy ounce (1 oz), i.e. 31.1 gram, has been used as a unit of weight on world exchanges trading in precious metals. It is in principal identical with the “British Imperial troy ounce“ unit which was adopted by the British in 1824 as part of the new system of measures and weights and used until 1971. Its predecessor – “English troy ounce“ – has been established as an official unit for coin mintage back in 1527.

The troy ounce is also used to mark weight of bullion coins which are most frequently struck in the following weights: one tenth, one quarter, one half of an ounce, an ounce. The weight of bullion bars is primarily stated in grams with the exception of one ounce bullion bar (the most popular among investors).


Fineness, or purity, refers to the content of gold in bars and coins and it is expressed in parts per thousand. The 999.9/1000 fineness indicates pure gold with a minimum of additives. A bar weighing 1,000 grams contains 999.9 grams of gold and only 0.1 gram of additives. Sometimes, this quality gold is also described as “four nines“ gold.

Larger differences in fineness can be found in coins. For example, selected coins of the Royal Canadian Mint’s Maple Leaf series are made of 999.99/1000 pure gold. However, compared with the “four nines“ gold the customer gets less than three thousandths grams of gold more on one ounce. Contrary to this, the South African Mint strucks its popular Krugerrand series coins from 917/1000 gold. It does not however mean that they contain less gold. The weight stated for these coins marks only the weight of the precious metal. Therefore one ounce Krugerrand coin weighs 33.93 grams. The additives increase the coin’s wear resistance and extend its life.

A carat, or karat, as the unit of fineness is used primarily in jewellery markings. The 999.9/1000 fineness of bullion bar corresponds to 24 carats.


Final selling price of bullion bars and coins depends on the current price at the London Bullion Market. We update the prices on ČM AURUM at regular intervals during the trading day (between 9 am and 3.30 pm on working days in the Czech Republic, except for days when the Exchange is closed).

The current price of gold at the commodity exchange (called “spot price“) applies only to one trade in the minimal quantity of 1,000 troy ounces, i.e. about 31.10 kg of fine metal. The margin of the manufacturer and distributor, so-called premium, is added to the spot price. This additional charge includes the costs of transport, insurance, manufacture of coins or bars, and the trader’s margin.

Gold is primarily traded in American dollars. For Czech investor, strong crown is an indication it’s time to buy because it reduces the price of gold and makes the purchase cheaper. Contrary to this, weak crown plays in favour of the sale of gold because it increases its price.

Czech Mint