It is a familiar sight in the media to see the prices of the four precious metals displayed. These are generally expressed in terms of dollars per ounce but may bear little resemblance to the price of one ounce of the metal in a piece of jewellery or in a small bar. So what does this number actually mean?

There are a number of factors that need to be considered to answer this. The first is that the price is quoted per troy ounce.