Troy weight

System of units of mass used for precious metals

A one troy ounce gold coin

Ingots of various metals, each weighing one troy ounce

A 1000 troy ounce silver bullion bar

Comparison of different pound systems

An engraving of a troy pound weight

Troy weight is a system of units of mass that originated in the Middle Ages and is primarily used today in the precious metals industry. The system is named after the city of Troyes in France, where it was first used. The troy weight system is distinct from the more common avoirdupois system, which is used for most other goods.

Units of Troy Weight

The troy weight system includes several units:

• Troy ounce: The troy ounce is the most commonly used unit in the troy weight system. It is equal to 31.1034768 grams. The troy ounce is used to measure the mass of precious metals such as gold, silver, platinum, and palladium.

• Troy pound: The troy pound consists of 12 troy ounces, which is different from the avoirdupois pound that contains 16 ounces. The troy pound is equal to 373.2417216 grams.

• Pennyweight: The pennyweight is another unit in the troy system, equal to 1/20 of a troy ounce, or 1.55517384 grams. It is often used in the jewelry industry.

History

The troy weight system has its origins in the Roman monetary system, which used bronze bars as currency. The system was later adopted by the Medieval European merchants and became standardized in the city of Troyes, a major trading hub. The troy weight system was officially adopted in England in 1527 during the reign of Henry VIII.

Comparison with Avoirdupois

The troy weight system differs from the avoirdupois system, which is used for most everyday goods. The avoirdupois pound is heavier than the troy pound, weighing 453.59237 grams compared to the troy pound's 373.2417216 grams. However, the troy ounce is heavier than the avoirdupois ounce, which weighs 28.349523125 grams.

Modern Usage

Today, the troy weight system is primarily used in the trading of precious metals. The London Bullion Market and other major exchanges use troy ounces as the standard unit of measure for gold, silver, and other precious metals.

Related pages

• Avoirdupois
• Precious metal
• Gold
• Silver

References

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  Troy weight gold 1 oz

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  Ingots of Ge, Fe, Al, Re, Os, one troy ounce each

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  1000 oz silver bullion bar

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  Comparison of pounds

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  Troy pound engraving