What is the difference between an ounce and a troy ounce?

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The use of ounces as a unit of measurement for gold dates back centuries. Despite the adoption of the metric system around the world, the ounce continues to be recognized and accepted as the preferred measurement for precious metals. However, an ounce is not just an ounce. The troy ounce, which is slightly heavier than the avoirdupois ounce (used for everyday measurements), has been the standard unit for weighing gold, silver, platinum, and palladium for many years. But what's the difference? The difference between an ounce and a troy ounce lies in the measurement systems they belong to and the industries in which they are commonly used.

Ounce: The ounce, denoted as "oz," is a unit of weight or mass used in the avoirdupois system, which is the most commonly used system of measurement in the United States for everyday items. In this system, 1 ounce is equal to 28.35 grams.

Troy Ounce: The troy ounce, denoted as "ozt," is a unit of weight specifically used in the precious metals industry, measuring precious metals such as gold, silver, and platinum. The troy ounce is part of the troy weight system, which is derived from the medieval trading system of Troyes, France. In the troy weight system, 1 troy ounce is equal to 31.1035 grams, which is slightly heavier than the ounce used in the avoirdupois system.

The key distinction between the two measurements lies in the specific industries and applications where they are used. The troy ounce is primarily employed for measuring precious metals due to its historical association with the industry. On the other hand, the ounce is used more widely in general commerce and daily life for measuring various items.

It's worth noting that when discussing the price or value of precious metals, such as gold or silver, the troy ounce is the standard unit of measurement. Therefore, when you see the price of gold quoted per ounce (oz) or if the weight of a gold bar specified in ounces (oz), it is typically still referring to troy ounces (ozt).