Diamond Carat Weight – Size Matters

What’s the first thing that comes to mind when people discuss diamonds? You are right if you guessed carat weight. Strange as it seems, the diamond’s carat weight alone doesn’t tell you anything about its proportions, beauty nor face up size. If that’s so, why is the carat size of a diamond ring the primary concern people care about?

The reason is simple. The value of a diamond is directly proportional to the carat weight and in many societies; it can depict the social status of the wearer. Larger diamonds are rarer in nature and therefore much more valuable as they are highly sought after.

How The Term Carat Came About…

The word carat has its origins stemming from the word carob. Back in the olden days, carob seeds were used as a form of weight measurement due to their size consistency and uniformity. To keep with traditions, the modern metric unit for measuring weight was renamed as carat.


The Relationship of Carat Weight With Value

Did you know that a huge percentage of diamonds used in jewelry actually weights less than 1 carat? To begin with, fancy color diamonds are already a rare find in nature and whatever limited roughs that come out of the ground command exorbitant prices. As a result, even a fraction of a carat can cause a significant difference in costs and value of the polished gemstone.

0.26 carat vs2 clarity cushion cut
fancy yellow orange marquise cut

While both diamonds have a similar color saturation and hue, the 0.26 carat VS2 cushion cut on the left costs $2,350 while the 1.14 carat marquise cut on the right costs $53,970. Even though the weight differences is about 4 times, the price differences is a staggering 23 times!

Obviously, the bigger the diamond, the more you would be expected to pay for the stone. Do bear in mind that the overall value of a diamond is also influenced by the other 3Cs: Color, Cut and Clarity. The rarity of a rough stone can directly impact the cost per carat of a particular diamond.

For example, a 0.90 carat VVS1 fancy brown stone would cost more than a 1.00 carat I1 fancy brown stone despite being smaller in size. Likewise, a tiny 0.09 carat fancy vivid pink can cost as much as a 1.16 carat fancy dark grayish greenish-yellow diamond because of the inherent color alone.

small fancy pink round brilliant
1 carat tri-color diamond

Does it surprise you that the tiny 0.09 pink diamond costs $7,120 while the significantly larger stone on the right costs $7,060? When you are comparing costs, it is important to be comparing apples to apples. Other factors apart from carat weight can contribute to the overall value of a fancy colored diamond.

Carat Weight Vs. Actual Face Up Size

People have the misconception that a bigger carat is always better and would result in a larger looking diamond. This isn’t true. The problem here is that most people get confused by carat weight and stone size because these 2 terms are frequently used interchangeably.

Strictly speaking, the carat weight of a diamond simply refers to how heavy the stone is. On the other hand, the actual face up view of a diamond depends largely on cut and shape. For example a poorly cut diamond not only hides weight in deeper stones, it can also suffer detrimental results in its optical performance.

Using the examples above, you can see that these 2 diamonds have similar physical dimensions and yet, they have totally different carat weights. This is largely due to the difference in which the diamond’s depth is cut to.

cushion diamond with 65.5% depth

lower depth percentage of 54.5%

The diamond on the left has a depth of 65.5% and a tablet 61.0%. It measures up at 7.67*6.85*4.49 mm.
The diamond on the right has a depth of 54.5% and table of 68.0%. It measures up significantly bigger at 8.14*7.30*3.98 mm

Here’s a tip for you to use this knowledge to your advantage. It is no secret that price jumps are the highest at the 1 carat mark bracket and most cutters do whatever it takes to keep a stone at a higher price bracket. This is why you often see diamonds with exactly 1.00 or 1.50 carats. Most people don’t know that is always done on purpose by the cutter’s design!

Since a diamond’s carat weight has the largest influence on pricing, it makes sense for people who are on a budget to “buy shy”. For example, a 0.90 carat diamond will be priced a lot lower than a 1.00 carat stone. Yet, in real life, the physical dimensions between these 2 stones may not be easily noticeable.

1 carat fancy yellow cushion cut
90 pointer cushion brilliant cut

In the example above, the 0.90 carat diamond on the left faces up with dimensions of 5.20*5.75*3.34 mm. Compared with the 1.00 carat diamond on the right (5.47*5.72*3.76 mm), it is only 0.30mm smaller in terms of width. This minute difference means that both diamonds look similar in size appearance to the eye. Yet, because the bigger diamond hit the “magical” 1 carat mark it costs 1.6 times more! That’s a whopping $2,590 more for practically no visual size differences.

Setting Designs And Diamond Shapes Affects Apparent Size!

The type of jewelry setting for a diamond can also create visual illusions of making a center stone look larger than it is. For example, a halo setting with many melee stones surrounding the main stone will appear like a single big stone when viewed from a distance.

In a similar manner, certain types of shapes appear larger than other shapes even though they are of the same carat weight. For examples, shapes like the marquise or pear usually have better spread as compared to shapes like the princess or round cut.

Here is a side by side comparison of 1 carat sized diamonds.

which shape has bigger spread?

The images are compiled to scale. Notice how some of shapes appear to look bigger?

The key takeaway here is: Size matters but it isn’t everything.

Fancy colored diamonds are expensive items. You need to do your own research and also possess a keen eye for details when shopping around. As always, if you need my help or advice on anything, do drop me an email and I’ll try my best to help you out.

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