Guide
What diamond criteria to favour ?
Diamond Carat
Visualize different carats of diamonds on a hand, a bust, an ear
Compare carat sizeHow to choose the carat weight of your diamond?
Diamond, a mass of light, is not represented. Any figuration of this precise stone is below, next to, reality. A loss. The figuration of the weight of the diamond? What the eye sees is not the weight, it is a volume, a brilliance. A diamond appears much larger than its diameter, by the play of brilliance of these facets.
What is the size of a diamond according to its carat weight?
The diameter? The carat, unit of measurement, measures weight and not diameter. A 1 carat diamond is not twice as large as a 0.50 carat diamond, only 25-30% larger (see table on the right), but costs more than double that. To help you better visualize the size of a diamond, we indicate in the table below the approximate diameter of a diamond (round brilliant shape) according to its carat weight.
In the Jewelry section of our site, on each of the jewelry cards (of solitaire, rings, pendants and earrings), you will also find a carat comparator that will allow you to visualize the visual effect of a diamond set and worn (on a hand, a bust, an ear), according to its carat weight and its diameter.
Please also note that the precise dimensions of the diamond are always indicated on the GIA, HRD or IGI quality certificate. You can see the online copy of the certificate by clicking on "see certificate" of each diamond card from our certified diamonds catalog.
Timeless collection
Engagement ring
4 Claws Classic
Solitaire diamond with 4 claws, a classic and timeless style. The highlighting of the diamond…
Ring
BRILLIANT
The perfect gift for your ever lasting love. Hand made french jewellery. Gold 750/000. Delivered in…
Pendant & Necklace
4 CLAWS
4 claw diamond pendant without bail. Forçat chain fixed by 2 rings on each side of the…
Wedding Band
RUBAN
Classic diamond wedding ring. 18 carats gold. Made in France. Delivered in a jewellery box. See…
Earrings
4 CLAWS CRADLE
Handmade diamond earrings, 4 claws heart-shaped cradle setting. Elegant exclusive design by…
Bracelet
ETERNITY
Diamond bezel bracelet. Very popular, a style that is both classic and contemporary. 18 carats…
Engagement ring
5 Claws Classic
Solitaire diamond with 5 claws. Solitaire offered in 18k white, yellow or pink gold (750/000) or in…
Ring
PRINCESS ROYAL
Style full of sparkle without being ostentatious. The dawn of passion and romance. Hand made to…
Pendant & Necklace
3 CLAWS B
Diamond pendant with 3 claws to enhance the stone as much as possible. Crimping carried out with…
Wedding Band
NOCEA
A modern style: diamonds are entwined in a crimped said "rail", a very contemporary…
Earrings
3 CLAWS PREMIUM
Handmade earrings with diamond belt based on mid height of the claws which are based on a rabbet.…
Bracelet
ERGO
Very modern, bright without being ostentatious. Pleasure of playing with the brilliance of…
How much does a diamond cost according to its carat weight?
A diamond, whether big or small, does not weigh much, but it is the factor that "weighs" the most on the price. This is why in our diamond catalog, we start with the weight and a price range, and then refine the other criteria.
There is no single answer to the often asked question: "what is the price per carat of a diamond? Two diamonds of the same weight often have very different values: it all depends on their certificate, quality of cut, shape, color and purity.
The question is then to know which diamond quality criteria you prefer according to your budget.
How much does a 1 carat diamond weigh?
The weight of a diamond is measured in carats. A 1 carat stone is equivalent to 0.20 grams. Diamond is such a specific material that it has its own unit of weight: the carat. This is conventionally set at 200 milligrams, or one fifth of a gram. The word comes from the Greek "keration", which is the seed of the carob tree: of fairly uniform weight, it was used as a unit of measurement in the Greek spice markets. These seeds of about 200 milligrams were considered as good units of weight measurement for weighing gems (diamond, sapphire, ruby, emeralds...) before the invention of fairly sensitive scales.
For more information, please do not hesitate to contact us at info@i-diamants.com or +33 (0)4 22 45 08 70.
The term has a different acceptance. In the appreciation of gold, the carat refers to the purity of the alloy: 24 carats correspond to 99% pure gold. The carat of gold is therefore the proportion of this precious metal in the jewel, pure gold being 24 carats and most jewelry to 18 carats, or three quarters of gold, or more exactly: 750 thousandths of pure gold and 250 thousandths of various alloys. 14 carat gold is made up of 585 thousandths of gold and 415 thousandths of various alloys. Recently, in response to the rise in the price of gold, the 9 carat title has appeared on the French market with the authorized appellation "gold". This gold contains only 375 thousandths of gold, i.e. 37.5% gold and 62.5% miscellaneous alloys. At i-diamants, we only offer 18 carat (750/000) gold jewelry. Other precious metals are also weighed in carats. For example, require that the platinum has a titre of 950/000, i.e. 950 thousandths of pure platinum and 50 thousandths of various alloys.
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How do you measure the carat weight of a diamond?
It is because the price of the material is high that the diamond is weighed accurately. The unit of weight in carat is a determining factor in the quality and value of a diamond. The value of a 1.00 carat stone is exceptionally greater than a 0.99 carat stone. Diamonds are weighed using electronic microbalances with a sensitivity of up to five decimal places. Verification of the weight of the stones throughout the diamond chain is also an important security measure.
How to calculate the carat of diamonds on a jewel already set?
Whether the diamonds set on your jewelry looks big or small, the simplest method (without having to loosen the gemstones in the jewelry) is to measure the diameter of each one. With the cross-reference chart above, you can determine the carat weight of the diamonds in your jewelry. Attention this rule works for white diamonds and colored diamonds (pink, yellow diamonds...), whatever the degree of purity and color, but does not apply to other gems, precious stones (Sapphire, Ruby, Emerald) or fine stones, whose density is different. For an exact measurement of the dimensions of gemstones, it is still best to go to a jewelry store and ask for the help of a professional jeweler, because even with a calliper, measurement errors are easy.
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Contact us nowWe recommend the following 5 selections
To help you choose, we recommend 5 categories of diamonds that correspond to different purposes: Volume (maximizing weight), Balance (compromise weight and quality), Perfection (maximizing quality), Cut of heart (the i-diamonds recommendation), Promotion (one-time price offer).
Volume effectmaximize the weight of the diamond relative to its price, I-J color and SI1-SI2 clarity
Choice of balancefavor a good balance of color / clarity: F-G / VS1-VS2
Perfectionmaximize the quality of the diamond with the best criteria of color and clarity: D IF
Favorite's choicediamond selected by i-diamants for its shine, D-E color, VS1 clarity, cut criteria all rated
Promotionsdiamond with a 5% promotion
Carats / Diamond weight
Move the diamond weight slider and view the rendering on a hand, chest or ears.
On the photo above, you can view different diamond diameters on a hand, by moving the slider. The fingertip of this hand is a size 53 (a measure quite common and which corresponds to an inner diameter of 1.68cm for the ring). The diameter of a diamond is proportional to its weight in carat (ct). The higher the weight, the larger the diamond. Carat is another unit of measurement of weight (1 carat = 0.2 gram).
On the photo above, you can view different diamond diameters on a woman's neck. The diameter of a diamond is proportional to its weight in carat (ct). The higher the weight, the larger the diamond. Carat is another unit of measurement of weight (1 carat = 0.2 gram).
On the photo above, you can view different diamond diameters on a woman's ear. The diameter of a diamond is proportional to its weight in carat (ct). The higher the weight, the larger the diamond. Carat is another unit of measurement of weight (1 carat = 0.2 gram).
Carat
mm (Approx.)
0,30 Ct
4,30 mm
0,40 Ct
4,60 mm
0,50 Ct
5,00 mm
0,70 Ct
5,70 mm
1,00 Ct
6,30 mm
1,25 Ct
6,90 mm
1,50 Ct
7,30 mm
Equivalence for round brilliant diamonds
Examples of different diamond measures
0,30 Ct
0,50 Ct
0,80 Ct
1,00 Ct
1,50 Ct
Diamond colours
Our recommandation
We recommend diamonds with a white hue between D (exceptional white+) and H (white) because the whiteness of the diamond increases its brilliance. From color grade I and J (slightly tinted) onwards, diamonds are slightly yellow-tinted: avoid on white gold and acceptable on yellow gold.
D-EExceptional white
F-GExtra white
HWhite
I-JSlightly tinted
K-MTinted white
N-ZVery tinted
Diamond clarity
Our recommandation
We recommend that you avoid choosing a Pique diamond, because inclusions are easily seen with the naked eye, alter the brilliance and can even weaken the stone. The clarities included in VS and SI1 are the most recommended , unless you have the budget to let yourself be tempted by IF or VVS clarities, which sign the diamond in its highest dimension: that of purity.
IFPure
VVSVery very small inclusion(s)
VSVery small inclusion(s)
SISmall inclusion(s)
PIncluded
IF : Pure
No inclusion inside the stone
VVS1 VVS2 : Very very small inclusion(s)
Very difficult to see with a 10X magnifying glass
VS1 VS2 : Very small inclusion(s)
Difficult to see with a 10X magnifying glass
SI1 SI2 : Small inclusion(s)
Easy to see with a 10X magnifying glass and difficult to see with naked eye
P1 P2 P3 : Included
Easy to see with naked eye
Diamond cut
When a diamond is well cut, light reflects from one facet to the other, making the most of the diamond's high refractive property. A less well-cut diamond lets some of the light escape.
Our recommandation
We advise you to choose a diamond with a quality rating equal to Excellent (EX) or Very Good (VG) to maximize the refraction of light and therefore the diamond brilliance.
EXExcellent
VGVery Good
GGood
FFair
PPoor
Most recognized certificates: GIA, HRD and IGI
Always ask to see the certificate before purchasing a certified diamond. For all of our certified diamonds, we display a link (GIA, HRD or IGI) that you can click to view the diamond’s full certificate.
We only offer natural diamonds accompanied by a certificate of authenticity and quality issued by one of the 3 most prestigious and world-renowned laboratories: GIA, HRD and IGI. The certificate number is engraved on the girdle (circumference) of all our HRD, IGI and GIA certified diamonds.
Laser engraving
The three major diamond certification laboratories HRD, IGI and GIA laser engrave the certificate number on the girdle (circumference) of the diamond. The certificate number is therefore engraved on all our HRD, IGI and GIA certified diamonds. This is a proof of the good match of the diamond and its certificate. The inscription is very small (to preserve the purity of the stone) and very difficult to read with the magnifying glass 10X.
If you order only the diamond (without the jewel), it will be delivered under seal in a rigid plastic pouch (see photo below) for diamonds certified by HRD or by IGI. For GIA diamonds, the seal must be specifically requested in the comments field during the ordering process.
Diamond Fluorescence
Fluorescence is a luminous effect that some diamonds exhibit when exposed to ultraviolet light. They show visible light, usually blue.
Our recommandation
Since fluorescence may in some cases give a milky diamond appearance, prefer a diamond without fluorescence ("None" or "Nil")
None or Nil
Absence of fluorescence
Slight or Faint
Little fluorescence
Medium
Medium fluorescence
Strong
Strong fluorescence
Very Strong
Very strong fluorescence
Diamond Polishing
When cutting the diamond, each facet must be polished. If a diamond has no scratches or very minor scratches on the surface, the polish is high. The better the polishing, the more it allows the transmission of light through the different facets of the diamond.
Our recommandation
We recommend choosing a polish rated Excellent (EX) or Very Good (VG) to ensure the best finish and shine.
EXExcellent
VGVery Good
GGood
FFair
PPoor
Diamond Symmetry
Symmetry describes the symmetrical accuracy of the facets of the diamond in terms of dimensions and angles, as well as the centering of the table and the centering of the breech point of the diamond. A higher level of symmetry creates optimal shine and scintillation.
Our recommandation
We advise you to choose a diamond with a symmetry rating equal to Excellent (EX) or Very Good (VG) to maximize the sparkle.
EXExcellent
VGVery Good
GGood
FFair
PPoor
