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.
What is a metric ton (or tonne)?
A metric ton, or tonne (t), is 1,000 kilograms, which is about 2,204.62 pounds. Most countries use it for cargo and bulk goods such as grain and ore.
The metric ton (1,000kg) is about 10% heavier than the US short ton of 2,000 pounds and about 1.6% lighter than the UK long ton of 2,240 pounds. Spelling it 'tonne' is the usual way to avoid the confusion.