Pure Gold

The chemical symbol for gold is Au, and its purity is defined in karats or its degree of fineness. If you are planning to invest some of your portfolio in gold bullion, bars, or rare coins, you will need to understand what makes gold pure. Obviously, the more gold there is in the gold, the more value it has.

You can find numerous objects that are called gold but actually contain very little of that precious metal. Or you can find gold bars that are virtually pure gold. In order to find the percentage of gold in an object, you have to multiply the number of karats by 100 and then divide that number by 24. A karat is 1/24th part pure gold. If you are buying an 18 karat gold ring, you would multiply 18 X 100 and then divide it by 24. Your 18 karat gold ring is actually only 75% gold. The other 25% is likely a mixture of copper and silver or, in the case of white gold, palladium.

Another Measure

Measuring by fineness is another way to determine how pure gold is. Fineness for any precious metal is the amount of that metal in parts per 1,000. Pure gold, containing no trace of any other metal, would be rated at a fineness of 1,000. Gold bullion in bars is usually stamped with its fineness measure, and, in order to be considered bullion, the bars must have a fineness measure of 99.5%.

Pure gold has many specific characteristics. It melts at a whopping 1945 degrees Fahrenheit. It's a relatively heavy metal, heavier than iron. Pure gold is extremely malleable; it can be drawn into extra-fine wire and hammered into nearly transparent thin foil. Pure gold keeps its brightness and color and will not rust, tarnish, or corrode like other metals. Gold jewelry made for the Pharaohs was in the its original state when recovered from tombs thousands of years after its owners were buried. Finally, pure gold is rare, and, as a result, is very expensive.