How much is my gold worth? How to test gold for its purity, and give it a value.

Source: from Dan Hurd Prospecting...
"Here is how anyone can value their gold, whether it is a gold nugget or a piece of gold jewelry. Also you can determine weather or not it is gold at all. In this video we will be using a "Scratch test" where we scratch some of the gold onto a piece of black slate and use different acids to see what acid dissolves the gold. once you know which acid dissolves the scratch of gold, you can figure out its Karat value. from there it is a simple online tool to determine the value of the piece of gold. What is it worth on the market can be a bit different the the actual gold value. As nuggets can sell for more than what the gold is worth."