What are Carats?
Carats are a unit of measure for diamonds and other gemstones. The word ‘carat’ comes from a carob seed, which was a standard comparator for gemstones in the days before high-tech weighing apparatuses.
The modern carat is much more standardized and weighs in at a mere 200mg, or one-fifth of a gram. The size of a one carat diamond will differ according to its cut because some cuts are deeper and narrow than others – these will appear small, when placed next to a wide shallow cut diamond.
A 2 carat diamond ring will hold a stone that weighs 400mg once it is removed from its setting. Do be aware though, jewelers do add separate stones together if they make one piece of jewelry.
For example, a pair of earrings each weighing half a carat will be sold as ‘earrings: one carat’, so do not be deceived by the considerably lower price you pay for having your carats broken up into different stones!
What are Karats?
Karats, on the other hand (and sometimes, confusingly, also spelled with a c!), refers to the purity of gold in a given piece of metal. There is no weight attributed to karats, a large chunk of metal could have a low karat rating, while an infinitesimally small piece can have the highest rating which is 24k. 24-karat gold contains only gold, with contaminants of up to 99.5% permitted before losing the 24k rating.
It is all but impossible to refine gold to an absolute 100% degree of purity, but anything that is rated 24k is sure to have a very high gold content and be worth, literally, its weight in gold. The next measure is 18k, in which 18 parts of the 24 are made from gold, with the remaining six comprising any number of other metals, from copper, silver, and other alloys.
14-karat, similarly, contains 14 parts are pure gold, and 10 are made from other metals or alloys. There are quite big jumps, from one carat to another, so jewelers will often use the ‘fine’ system in which pure gold (if it existed) would be 1000-fine.
Next time you watch a bank heist movie, pay attention to the gold bars the robbers are exulting over: they often have ’24k’ in large font at the top on the front face of the gold bar, with a number, usually anywhere between 950 and 997 – this is the ‘fine’ rating and it gives a much more accurate measure of how much pure gold you are holding. Or trying to hold, anyway!
Do They Really Get Muddled?
Yes, it is possible for people who do not work within the jewelry industry, to assume that one carat is the same as one karat. In fact, it is easy to see, now you know the difference between them, that a 2 carat diamond ring is much more valuable than a 2 karat anything else!
So diluted a piece of metal would barely have any real value – and in the USA it would not legally be called gold at all! The minimum in the USA is 10-karat gold (so 14 parts other metals), while in the UK and much of Europe, 9-karat gold is the ‘cheapest’ gold available.