“Here is some information to help when you make that visit to foreign territory known as the jewelry store. It has to do with the difference between the terms carat and karat. Both are relevant, and they are different.
“Let’s start with carat with a ‘c.’ A carat (abbreviation ct.) is a weight measurement for precious gemstones, especially diamonds. Many people think the carat refers to the size of the gemstones. That is not completely the case. The carat is a measurement of weight or mass. So, it makes sense that a larger stone would weigh more, thus having more carats. While size does affect the weight of the gemstones, they can have varying density, so weight, along with the purity of the gemstone is what determines the price of precious stones.
“For those who like numbers, a carat is a unit of weight equaling 200 milligrams Continue Reading. To put this in perspective, to have one pound you would need 453 grams, or 453,000 milligrams. Another example is that a person weighing 170 pounds would weigh 385,050-carats.
“The other karat with a ‘k’, is used to measure the purity of gold. Gold itself is very soft, and like silver, it needs to be alloyed (combined) with another metal or metals to make it stronger and consequently less expensive.
“The carat became legal standard for gold on April 1, 1914 and only implied weight.
“The term ‘karat’ comes from the old German gold coin used about one thousand years ago. Karat is a unit of measure for the fineness of gold, equal to 1/24 part. Each karat indicates 1/24th of the whole. So if a piece of jewelry is made of metal that is 18 parts gold and 6 parts copper, that is 18-karat gold. The abbreviation for karat is kt.
“Is 24 karat gold (pure gold) the best quality one can buy? It depends on what you’re using it for, since it tends to be soft and not very durable. It can be susceptible to scratching and can be damaged easily. That is why the gold is combined with metals such as silver, copper and zinc to strengthen it.
“Although the karat does determine the value of the gold, it does not indicate the price we will pay when we go searching for that new bright shiny object. Precious metals are measured in troy ounces with one troy ounce equaling about 31.1 grams. There are 12 ounces per troy pound.
“In general, carat refers to mass and karat refers to gold purity. But, beware that in some places carat is the term compared to both mass and purity.
“Also, don’t forget that there is a word caret that refers to spacing symbol or mark used in written or printed material to show the place where something is to be inserted.”
This article first appeared in the November 25, 2011 Berthoud Weekly Surveyor.