What are Troy Ounces?
A troy ounce is the unit gold, silver and platinum prices are quoted in. It is about 10% heavier than an avoirdupois ounce, but a troy pound has only 12 of them.
One troy ounce is equivalent to approximately 31.1035 grams, which is about 10% heavier than a standard avoirdupois ounce. The term "troy" originates from the city of Troyes in France, where this unit of measurement was historically used in the trade of precious metals.
There is more than one type of ton
There are three common types of ton; the metric ton (tonne), long ton and short ton.
The metric tonne, also spelled metric ton, is 1,000 kilograms or about 2,204.62 pounds, and it is the one used in countries that have gone metric. More on this unit here: Metric Tonne.
The Long Ton, also known as the Imperial Ton, is the ton of the United Kingdom and is equivalent to 2,240 pounds or about 1,016 kilograms. Further information can be found here: Long ton (Imperial ton).
The short ton is used predominantly in the United States and is equivalent to 2,000 pounds. This unit of measurement is commonly used in industries such as shipping, construction, and agriculture. More information here: Short ton (American ton)