Hacking the 4Cs: Carat of a Diamond
The lone objective parameter of grading diamonds, the carat refers to the weight or mass of the precious rock. It is true that most of us define or even dream of diamonds and gemstones based on its carat or weight. Mostly because carat weight of a diamond is easy to understand the price with, but carat weight and price are not always related.
Diamonds are weighed in carats and it is almost equal to the weight of a paper clip and as magic weight. Diamonds are collected as rough parent rocks, which are then polished to remove the inclusions, cuts and flaws to craft a tiny or moderate diamond. The expensive price-tag of diamonds owes it to neutralizing the cost of wasting diamond while polishing to get premium and flawless diamonds, most aspiring to be of the magic weight.
What does Carat of a Diamond Mean?
The physical weight of a diamond is defined as the carat of a diamond. Since its first categorization in 1913, there has been many ways and means of dividing diamonds based on weight. Carat is used to measure diamonds and gemstones. Abbreviated as TW or total weight, weight of a carat is the result of the skills of a diamond cutter. The same is why round-figure accurate rates are hard to achieve and the same is termed magic weight as well as highly priced.
For example, 2 carat diamond needn’t be equal to the price of two 1 carat diamonds or 1.5 carat diamond plus 0.5 carat diamond.
Roughly 200 milligrams, carats are further divisible into 100 sub weights. As even a fraction of a weight or lack of weight adds to the look, crown and diameter of a diamond, precise measurements that account for up to hundred decimal places constitute the carat of a diamond. All diamonds below one carat are referred in pointers such as a 0.75-carat diamond can be termed as a 75 pointer while a diamond with 1.05-carat rock will be termed ‘One Point Oh Five’ Carats.
With rarity, size, color, glow, cut, shape and clarity, the price of a diamond varies. This is why two different diamonds of one accurate carat weight can still have varied prices. In addition, bigger diamonds are harder to find and hence the rate peaks exponentially for bigger rocks.
History of Diamond Carat
A few hundred years back, carob seeds were used to sell and buy gemstones. In fact, diamond geezers usually brought two different carob seeds to the market, out of which one used to be small and the other, big. When selling, the geezer used bigger carobs and small carobs while buying the gems. This made the selling be of lesser worth and buying to be of higher worth.
To elaborate, even different countries had a different variety of seeds and grains to measure the fractional weight of gems.
Etymologically derived from the Latin word- carato or ‘small horn’, referred to the seeds of carobs that were believed to have null variability in mass.
· Refiner’s Carats
There were two varieties of UK Refiner’s Carat- Ounce and Pound Carats. The former was divided into 24 ounce weight carats that were equal to 20 grains each. The latter was divisible as 24 pound carats of 240 grains each. Pound Carat was equal to four pounds of grains with 60 pound grain for each while the Pound Grain itself was 4 sets of 15 grains each. The ounce carat was equal to 20 grains each while the ounce grain was 4 ounce quarters weight 1 ¼ grains for each.
· UK Board of Trade
A gem measurement of the UK, one carat was equal to 3 1647/9691 grains or 3.170 gr. Later, the same was amended to 3 17/107 or 3168 g. Each carat according to the board of trade was 4 grains of diamond.
· Greco-Roman
The known unit for measuring gemstones was in solidus with 72 coins equating to one roman pound, also equivalent to 327.45 g with 1 solidus equal to 24 siliquae. One siliqua equated to 189 mg, making one roman pound just under 5 g.
Carat Scale of Diamonds
Carat (ct) is different from Karat (kt), where the former is used for measuring diamonds as well as gemstones while the latter is a unit to measure gold. Carat in the case of diamonds does not follow one relation with the size of the rock. Carat is the weight or mass of the rock, while the size of a diamond refers to its diameter in millimeters.
It is impossible to assume that for diamonds of one size, the diameter and crown measurement will be static too.
- One Carat= 200 mg
- One Gram= 5 Carats
- One Pound= 2268.2 Carats
Carat Weights are analyzed based on different equations for the varied size of diamonds. A common equation to determine the weight of a diamond based on the shape and aspects are
- Round
Depth X 0.0061 X Average Diameter 2 X Girdle Correction %
- Asscher
Depth X Length X Width X Girdle Correction % X 0.0080 X Weight Correction %
- Cushion
Depth X Length X Width X Girdle Correction % X 0.00815 X Weight Correction %
- Oval
Depth X Length X Width X Girdle Correction % X 0.00625 X Weight Correction %
- Emerald
Depth X Length X Width X Girdle Correction % X 0.0092 X Weight Correction %
- Marquise
Depth X Length X Width X Girdle Correction % X 0.00565 X Weight Correction %
- Pear
Depth X Length X Width X Girdle Correction % X 0.00615 X Weight Correction %
A way to determine the price of a diamond is by collecting the selling price of your diamond, then dividing it by the total carat weight of your diamond.
Exemplifying, if your diamond is 0.75 carats, at a selling price of $7500, the per carat weight will be $7500/ 0.75= $10,000. With respect to the increase in carats, the price rise of a diamond is erratic. To simplify, one in a million of mined rough diamonds are suitable to cut a perfect magic weight of 1.0 carat of diamond.
An important determiner of the price of a diamond also is its perfect weight. Say, your diamond is 0.90 carat, then the diamond is also 0.10 less than the magic weight of 1.00. If you purchase a 1.0 carat stone, the difference between your earlier stone and the magic weight stone will be a disproportionate raise.
What should you worry about?
If you have two diamonds of equivalent carat weight, but one is colored or blurred, the prices of both will not be the same. Do not assume the price of your diamonds based on their look, but shape, flaws, colors and characteristics.
You can get ripped off if you purchase diamonds of magic weight, if the rock is not accurately measured. Often, people pay lump sums for magic weighing diamonds, but only when they appraise the stone do they realize that the stone is not actually magic weight. To know more about the magic weight of diamonds, click here.
A disadvantage of magic weighing diamonds is that in the future if you decide to re-polish or re-cut, your magic weight will disappear and equate the bonus sum you paid for the rock to be worthless. In addition, look out for any blemishes due to the over polishing or careful polishing of the stone. Often, diamond cutters leave inclusions within the rock, trying desperately to achieve the magic weight.
Today, there are treated diamonds that are filled with silicone to match bigger sizes, yet look big and shimmering as large diamond, at the price of a small. You must take care to appraise your purchase and verify if the diamond that you acquired is worth the price you paid for. To know more about bigger diamonds for half its price, check the reputed diamond geezer- Freddy Diamonds Review from DPA here.
What should you be proud of?
Magic Weight refers to a diamond cutter’s ability to cut out a rock of perfect round-figured weight like 1.00 ct or 5.00 ct. If your diamond is an accurate measure correlating to the magic weight, you should certainly be proud of it. Surely, magic weight does not determine the depth of your love or marital happiness, but surely the perfect weight of the engagement ring also signifies the magical balance of your relationship.
How does the grading of Carat weight of diamonds take place?
For every shape of a diamond, the carat scale differs based on the average diameter, depth of the diamond and girdle correction. Nevertheless, unlike centuries’ ago, the carat size does not differ and it is clocked at 0.2 g each.
One easy way to understand the carat scale of diamonds with respect to a few sizes and the diameters with respect to specific shapes are:
| Carat | Common Name | Size- Round | Size- Pear | Size- Emerald | Size- Marquise |
| 0.20 | 1/5 | 3.8 mm | 4.0 x 2.0 mm | 4.0 x 3.0 mm | 5.0 x 2.0 mm |
| 0.25 | ¼ | 4.1 mm | 4.5 x 2.5 mm | 5.0 x 3.0 mm | 5.5 x 2.5 mm |
| 0.50 | ½ | 5.2 mm | 6.0 x 4.0 mm | 6.0 x 4.0 mm | 8.0 x 4.0 m |
| 0.75 | ¾ | 5.9 mm | 7.0 x 5.0 mm | 6.5 x 4.5 mm | 9.0 x 4.5 mm |
| 1.00 | 4/4 | 6.5 mm | 8.0 x 5.5 mm | 7.0 x 5.0 m | 10.0 x 4.75 mm |
| 1.50 | 1 ½ | 7.4 mm | 9.0 x 6.0 mm | 8.0 x 6.0 mm | 11.0 x 5.2 mm |
| 2.00 | 2 | 8.2 mm | 10.0 x 6.5 mm | 8.5 x 6.5 mm | 12.0 x 6.0 mm |
| 2.50 | 2 ½ | 9.0 mm | 11.0 x 7.0 mm | 9.0 x 7.0 mm | 13.0 x 6.5 mm |
| 3.00 | 3 | 9.3 mm | 12.0 x 8.0 mm | 10.0 x 8.0 mm | 14.0 x 7.0 mm |
What Carat of Diamond will look good for just-engaged Couples?
The rarity of the diamond grows with its bigger size and hence, the price of diamonds increases with the larger magic weight of diamonds. For engagement rings, diamonds transform into the epitome of one’s love for the partner. If you’re a diamond buff, the magic weight of the rock must be an essential, but to minimize your budget, you can use a collection of stones to achieve a total carat weight of the ring plus its rocks, rather than the rocks alone.
It is definitely the highlight when you claim that your engagement rock is a 5.00 carat conflict free red rare rock!
The considerations for Carat Grading
As per the metrics of grading the carat weight of a diamond, there are many factors that affect it. With respect to the shape and aspects of the diamond, the weight of the diamond can differ.
Diameter Correlation with the diamond
With the metrics and equations shown above, it is easy to understand that there is a direct relation between the diameter and the weight of a diamond. This is based on the fact that it is impractical for a diamond of 0.5 carats to have more area than a 10 carat diamond! As one carat diamonds can vary in its diameters size from 5.60 mm until 6.60 mm, the look of a diamond does not justify the increase in weight.
Cut Grade and diamonds
Perfect cut of diamonds is used to determine the perfect look of the diamond. If your diamond is of magic weight or a round-figure, it is hard to find a superior cut grade, but the same looks better with a high cut grade and terrible with a low cut.
The Bottom Line
From being equivalent to the fruit of a carob tree to grains and nano weights, diamond grading has evolved much over the past centuries. Today, the value of a diamond is not determined based on one aspect alone, but many. Being one of the vital 4Cs, carat or weight of diamonds is used to determine the physical value of the diamond’s mass. While magic weight can add a drastic increase to your bill, diamonds should be bought with a highlight on its value and lack of value, than weight alone.