The Difference between 14K and 18K Gold
In its purest form, gold is too soft to withstand the wear and tear of
everyday use. So, alloys are added to make gold more durable. The less
alloy, the higher the cost.
14 Karat gold is fourteen parts gold and
ten parts of another alloy (usually silver, zinc, or nickel), or
58% pure gold
18 Karat gold is eighteen parts gold and six parts of another alloy, or 75% pure gold.