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Diamond Carat
Diamond Carat Weight is one of the 4 Cs of diamond quality evaluation. Together with Colour, Cut, and Clarity, Carat Weight determines the value and price of a diamond. When you browse our website for diamond jewellery, you will find details of the total carat weight of the diamonds used in the piece given in the description box. This guide will help you understand what a diamond carat weight is and how to visualise and match the size of diamonds in a piece of jewellery with its carat weight.
What does carat weight mean in diamond jewellery?
We often hear about celebrity engagement rings in terms of carats "... Michael Douglas gave Catherine Zeta-Jones a whopping 10-carat rock!" Have you wondered what ‘carat’ is?
A diamond's weight is measured in carats. In relation to other quality grades of the diamond, Carat Weight has a direct influence on a diamond’s price. When you buy diamond jewellery, carats influence the price when the diamond's cut, clarity and colour grades are good.
Carat Fact: Gemstone weight is expressed in carats. It is spelt with a 'c' and abbreviated as c or ct.
Gold purity is expressed in Karat spelt with a 'K' and abbreviated as k or kt.
A one-carat diamond weighs 200 milligrams or 0.2 grams.
When a jeweller refers to a large stone that weighs a ‘one full carat’ he means that it weighs 200 mg or 0.2g.
One carat has 100 points called cents. A diamond weight of 100 cent is the same as a 1-carat.
A jeweller may describe the weight of a diamond below one carat by its 'cents' or ‘points’ alone. A 0.30ct. diamond is called a thirty pointer, a 0.50ct. diamond is a 50-cent diamond or half-carat diamond and a 0.75ct. diamond is a 75-cent or three-quarter-carat diamond.
In a piece of jewellery set with more than one diamond of different carat weights, the total carat weight (CTW) of all the diamonds is given in the description. The total carat weight influences the price of the piece.
In olden times, early gem traders sold diamonds against the weight of carob seeds. These were tiny uniform-sized seeds that weighed 200 mg approximately. The word "carat" is believed to be derived from "carob". The modern carat system, which is highly accurate, was developed by the Gemological Institute of America (GIA).
Is the diamond size and carat weight the same?
Diamond size is different from diamond carat weight. Terms like 'carat sizes' are misleading. While the weight of a diamond is measured in carats the size of a diamond is its dimensions measured in millimetres (mm), centimetres (cm), or inches (").
Diamond size in millimetres and diamond carat size don't change proportionally. Generally, a diamond that weighs more will look larger than one that weighs less. If all other aspects are equal, the large diamonds will have a greater carat weight and will cost you more than the smaller diamonds. However, you cannot conclude that a 2-cart diamond is twice the size of a one-carat diamond! If you look at a diamond size chart for the round shape, you will see that the dimension of a 1ct. diamond is roughly 6.5mm while a round diamond of 2ct. is 8.2mm (not double).
Diamond Carat Size Chart
The diamond Carat Size Chart is a visual representation of different diamond carat weights and the proportionate diameter of the diamond's girdle in mm. Diamond sizes will differ for different diamond shapes.
The chart here is a diamond carat guide to help you understand the approximate size of a stone to its carat weight.
Do diamonds of the same carat weight but different cuts look alike?
Diamond shapes influence the appearance of a diamond's size more than its carat weight. Different diamond shapes of the same diamond carat can look bigger or smaller according to their cut.
♦ A round brilliant and oval-cut diamond weighing 1.0 ct. each, the oval stone will look larger than a round brilliant stone.
♦ An emerald-cut diamond and a marquise diamond have the largest size profile in relation to carat weight.
Is a higher carat weight better when buying diamond jewellery?
Diamond carat weight does not affect the value of diamonds as much as their colour, cut, and clarity. The value of diamonds per carat is influenced only by these 3 C's. For two diamonds of equal carat weight, the diamond that ranks higher on the clarity scale and has a better cut and colour grade will cost more than the other.
What is the best carat weight for an engagement ring?
A diamond engagement ring might be the first diamond jewellery that you purchase. And that's when you are forced to consider diamond carats! It is a significant purchase, and you will want to get the best value for your money.
So, what's the best carat weight for diamond engagement rings?
In the solitaire design, the most prominent feature is the single stone, which is the focus of attention in the ring. The most popular carat weight for diamond solitaire engagement rings is 1.0ct. But, if budget is a constraint, you can buy a beautiful ring in smaller carat weights using the magic numbers explained below!
Magic Number Chart
Buying Tip Buy 0.1ct. below these magic numbers to get a better diamond price per carat.
| 0.90ct | 1.0ct | 1.5ct | 2.0ct | 3.0ct | 4.0ct | 5.0ct |
Understanding the magic number in diamond carats
According to the International Gem Society (IGS), some carat values are called "magic numbers". These magic sizes are the points at which there is a jump in the per-carat price of the same quality. For example, there is a considerable jump in price between 0.89ct. and a 0.90ct. diamond, although there is little difference in their appearance; they are virtually the same size. Likewise, a 0.99ct. stone costs much less than a 1.0ct. diamond. However, if they are placed next to each other, they look the same, and you cannot tell the difference in size.
What to look for when you buy a diamond ring
Choose the metal and then the ring design. A gold ring or a silver one? Do you want to buy a solitaire diamond ring or a ring with more than one diamond?
Check the diamonds' colour, cut, and clarity. You will find these details in the description of the ring if you are browsing online.
We recommend that you give importance to these 3 Cs of diamonds even if you buy a smaller diamond. A small diamond of a higher colour, cut, and clarity grade is always more beautiful and satisfying to wear than a large diamond that lacks brilliance, fire, and sparkle due to its inferior grades.
But most importantly, choose the diamond you like at a price you feel comfortable with.
If you need personal guidance, you can always reach out
Have no worries when you shop online for diamond jewellery at The Jewellery Room. Every day we have the honour of helping customers from all over the world. Our jewellery experts will do whatever it takes to find the perfect fit and size for the jewellery you're looking for. And please remember if you are still in doubt, you can shop safely with us.
We guarantee you can always exchange your purchase within 30 days.