The Beginning of the Troy Ounce
The troy ounce, is a method of weights and measurements known as the troy weight system. The name came from the city troy in France. On May 19 1828, United States Congress assigned the British Imperial troy ounce as the primary system of measurement for gold. Since then the term troy ounce has been adopted in replace of The British a Imperial troy ounce.
Now when you buy 10oz ounces of gold you are buying 10 troy ounces. Other precious metals are also using these weighing systems. Such as Platinum, and Silver and good Ol' Bullets. Well at least the powder. All the things Americans have survived on for over a century.
The Troy Ounce More Facts to Consider
One troy ounce is equivalent to 31.1034768 grams. There are 28.3495231 grams in a standard ounce. So if your buying gold from the street dealer don't let them fool you. (Which I never recommend. You need security and structure when investing in gold.)
Ne way when buying gold be sure your buying in troy ounces at the standard rate. Vs one standard ounce. Which would be a 3 gram loss. That's a $130 loss may not seem like much, but it's not a troy ounce who's says it's really 99.9% pure gold. Which is what the gold market price is based on. So remember if your buying gold at the best prices, make sure your buying based on troy ounces, and not just ounces.
Find more information on gold and the troy ounce visit Wikipedia troy ounce.