Gold carats typically refer to a measure of gold purity, with 24k being the highest. Before moving on, it should be explained that carats, in actuality, refers to weights of stones, rather than purity of metals. In terms of gold purity, the correct term is karats. However, many people refer to gold carats when they are actually discussing gold karats. The two terms are often confused and very few may even realize there is a difference in the spellings.
Gold karats are necessary to inform the consumer of the purity of gold because hardly ever is gold in its purest form. Rather, it is mixed with other metals to create what is known as an alloy — a mix of two or more metals. Most people, therefore, like to understand just how much gold they are getting when they are buying gold jewelry. The higher the gold karats, the more expensive the jewelry is likely to be.
However, it should be noted that just because the gold karats represent a higher number does not mean the jewelry is any better, shinier or prettier. Rather, the term simply means there are more alternative metals used if the number is lower. To be half gold, the gold carats must be 12k. However, it is extremely uncommon, but not impossible, to find such a rating.
The most common ratings for gold karats are 10k, 14k and 18k. While there may be some variations, these represent the bulk of gold jewelry sold throughout the world. Choosing how many gold karats to buy for a certain piece may depend more on personal preference and desired durability than anything else. However, for those who think they should get the highest purity of gold they can afford, that may not be the best decision.
To explain, consider why gold is often mixed with another metal in the first place. It is because the metal is very soft. It is so soft, in fact, it can be shaped and molded by hand. Any pure gold jewelry, therefore, would not stand up to practical use with it being that soft. Therefore, it must be mixed so that it can stand up to the rigors of daily use. Otherwise, it would quickly become misshapen and scratched.
Even the higher concentrations of gold can become bent and scratched relatively easily. That is why many, even though they may be able to afford higher purities, tend to go with 10k or 14k gold. In most cases, 10k gold, is considered the lowest purity of the metal that can be made and it still be referred to as gold. Therefore, the gold in jewelry is seldom diluted any more than this.