Pennyweight

Irish pistole

Medieval, Coin Weight, Irish 8 Pennyweight (FindID 835186)

Irish pistole

Pennyweight (dwt) is a unit of mass traditionally used to measure the weight of precious metals, such as gold, silver, and platinum. The term originates from the weight of a silver penny in medieval England, which was standardized as 1/240 of a Troy pound. A pennyweight is equal to 24 grains or approximately 1.55517384 grams. The use of the pennyweight is closely associated with the Troy weight system, which is different from the more common avoirdupois system that is used for everyday weight measurements in the United States and around the world.

History

The concept of the pennyweight dates back to the times of the Anglo-Saxon kingdoms, where the weight of a silver penny was a standard unit of measurement. With the introduction of the Troy weight system, which is believed to have originated in the French town of Troyes in the Middle Ages, the pennyweight was incorporated as a key component. The Troy system was adopted by the United Kingdom for the minting of coins and eventually by other countries for the measurement of precious metals.

Usage

Today, the pennyweight is primarily used in the jewelry and dentistry industries, as well as by goldsmiths and silversmiths, for measuring precious metals. Despite the widespread adoption of the metric system, the pennyweight remains a standard unit of measure in these fields due to its historical significance and the tradition of the trade. It is also commonly used in the valuation and sale of precious metals, where the purity and weight of the metal are critical factors in determining its value.

Conversion

The pennyweight is part of the Troy weight system, which includes other units such as the Troy ounce and the Troy pound. The conversion rates between these units and to the metric system are as follows:

• 1 pennyweight (dwt) = 24 grains
• 1 pennyweight (dwt) ≈ 1.55517384 grams
• 20 pennyweights (dwt) = 1 Troy ounce
• 240 pennyweights (dwt) = 1 Troy pound

Contemporary Relevance

While the use of the pennyweight is less common in general commerce today, it remains a vital unit of measurement in the trade of precious metals. Its persistence highlights the blend of tradition and precision in industries where the historical context of measurement units adds to the richness of the trade practices.

See Also

• Troy weight
• Avoirdupois system
• Gold
• Silver
• Platinum
• Jewelry
• Dentistry

Pennyweight Resources
Latest articles Most recent articles Ongoing trials	Wikipedia