Like every industry, the gemstone and jewellery industries have their own double speak. These are words that sometimes only those in the profession can understand and are possible to catch buyers off-guard; the words carat and karat are my examples.
In this post we are going to discuss the difference between carat and karat. Two different things that the majority of consumers dont actually know the difference between, or even presume their meaning for something completely un-related.
What is a carat?
Carat with a C is the weight of a gemstone like diamonds and rubies. Because it's not actually explained by (in my personal opinion) the terrible, majority of sales people behind the counter at jewellery stores; its actual meaning is often left up to the consumer to self interpret.
If you were to ask the majority of women out there right now what carat meant in accordance with their engagement ring; they would most likely say it's the gemstones size. Though wrong, they are also right to a certain degree. Because of how gemstones must weigh more if they are bigger, yes the carat of the stone does go up with size but that's not actually how you measure the size of the stone. Not that I want to delve too much on it here however, but the size of a stone is actually measured across the girdle (its widest part). Carat alone can't be used to determine the size of a stone because of the fact some cutters out there try to hide more weight in the stone by making the pavilion (the bottom part of a cut gemstone) slightly bigger to just tip the scales from it being a 0.9 carat stone to being a more valuable 1 carat stone (This is called a 'fat belly' and can be classed as a flaw (though intentional) in the cutting process).
So hold on, what exactly is a carat? 1 carat is equal to 0.2 grams and the origins of the word has a long history of being passed around different cultures and languages. Carat being used in English since the 15th century which in turn was taken from the Italian word carato, which comes from the Arabic word qīrāṭ قيراط. In turn, the Arabic world burrowed this from the Greek word Kerátion κεράτιον 'carob seed'. The carob is an evergreen tree around the mediterranean and the middle east that produces edible seeds that just so happen to weigh around about 0.2 grams. You can just imagine the many interweaving cultures of the ancient world that used to sail the turquoise waters of the mediterranean; trading rarities like the emeralds of egypt, using the seed of the humble carob tree to determine weight and therefore value, at such a finite scale.
What is a karat?
Karat with a k has nothing to do with carat with a c, infact they are so unrelated that karat has nothing to do with gemstones. Karat is the purity of gold. The karat of gold is on a scale of 1 to 24, 24 being pure gold, 1 being ... definitly questionable gold.
So now you can see why it's very confusing when a first time buyer walks into a store to buy a ring for example and asks about it. Perhaps they have heard the word carat out there and just to get some kind of perspective on a piece, ask how many carats the ring is. Because they are pronounced exactly the same carat and karat, who knows what you're actually asking questions about! You might be asking how many carats the gemstone is and know that the average size of a engagement ring stone is 1.2 carats, but then when the sales person says the ring is 18 karats...you must think you're about to get the deal of the century.
I am pulling your leg slightly here, because when you walk into a shop and ask about carat, the sales person normally knows you are talking about carat, not karat. Especially in the American market, the karat of gold for example in America is almost always 100% of the time 18 karats because it's the standard of the industry over there. However if you were to come to Europe, the karat for gold in pieces can be up to 24 in some cases so it's often worth asking the question seperate, what is the carat of the stone and what is the karat of the gold.
For my American friends across the pond, don't feel cheated that you're only getting 18 karats. 24 across the world is mostly reserved for investment purposes only and so even though pieces can contain 24 karat gold, it's not often. Due to the fact pure gold is so soft and not as durable as its 18 karat alloy equivalent, 24 karat makes for poor day to day jewellery because of all the little nicks and bangs it would have to endure. This is why 18 karat gold is accepted as a standard because it gives the pieces it's used in high quality endurance and durability to keep up with demanding consumers.
Conclusion
So, we now know the difference between carat and karat. Carat is the weight of a gemstone and karat is the purity of gold. So now we know that if a sales person was to say, this is a 2 carat princess cut diamond set in a 18 karat gold fitting; that the 2 is the weight of the stone and the 18 is the purity of the gold collet, lower bezel and shank (aka ..the ring part, haha)