Suppose that you are about to buy a diamond and are looking at several stones that the salesperson is showing you. Do you know that all those 1-carat diamonds in front of you may not be exactly 1 carat?
Advertised Carats Are Approximate
Although diamond carat weight is expressed in standard values such as 0.5, 0.75, 1, etc., in reality, there is rarely a stone whose weight corresponds exactly to one of these numbers.
A 1-carat diamond may actually be 0.95 or 1.05 carats. That’s why you shouldn’t expect two diamonds with the same carat tag to be perfectly identical in terms of weight.
It is actually perfectly normal for a diamond’s carat weight not to be an exact standard number. Usually, when a diamond’s carat weight is advertised, it is mentioned that the number is approximate.
This is normal practice and is usually disclosed; you can always find the exact carat weight of a diamond in its certificate (or grading report).
Why Not Cut Diamonds in Exact Carats?
It is often not possible to cut a diamond so that its carat weight conforms exactly to a standard value.
The jeweler cutting the diamond crystal will usually try to come up with one or more stones that are of as high quality as possible.
For example, a stone’s carat weight may be intentionally reduced by cutting out segments that contain a lot of natural flaws, thereby improving the diamond’s clarity.
Or, the jeweler may get rid of some parts of the crystal in order to create a more proportional cut that maximizes the sparkle of the stone.
However, the cutter will also try to use as much as possible of the raw material and minimize scrap. As a result, the cut stone will have a carat weight that will be close to one of the standard values, but there will always be some deviation.
What Is the Normal Carat Variation?
Usually, a diamond’s real weight will be within 0.06-0.08 carats of its advertised value.
For instance, a 0.94-carat diamond will be sold as a 1-carat stone.
Or, a diamond claimed to be 0.75 carats may in fact be closer to 0.8 carats.
You can always ask the salesperson at the jewelry store about the exact carat weight of the diamonds you are being shown.
You can also check this number in the diamond’s grading report – it should be mentioned there.
How Visible Is the Difference in Carat Weight?
Of course, if you compare a 0.75-carat diamond with a 1-carat one, you will notice the difference.
However, when the deviation is between 0.05 and 0.1 carats, it is hardly detectable.
If a 0.95-carat diamond is put next to a 1.02-carat stone, for example, chances are you will have to look really hard to spot the difference.
And when a 0.95-carat diamond is worn, nobody will notice that it is not exactly 1 carat.
Carat Weight Variation and Prices
You should expect to pay a little bit more for a diamond that goes a little bit above the 1-carat or 0.5-carat mark (or above any standard value for that matter).
This works both ways, though. If a diamond is 0.05 carats shy of 1 carat or any other standard weight, you can expect to pay less.
That’s a useful tip to know when shopping for diamonds – just ask to see a number of stones of your desired carat weight, and pick one that is slightly lighter than the standard number.
As already mentioned, the difference will not be noticeable with the naked eye, but you will save some money.