What is the process of grading diamonds?

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Your search for the perfect ring for your perfect someone takes you to a jewelry store. It’s not surprising that you’ve prepared yourself for the cost, but when it comes to actually paying, all you can think about is, “How in the world can they determine if a diamond is “good” or not?”

In grading and determining diamond price, four characteristics known as 4c’s are most important: diamond color, clarity, cut, and carat weight.

Besides the 4 Cs, other characteristics can also be included on a diamond certificate, such as its symmetry, polish, light return, and fluorescence.

How Is Diamond Color Graded?

A popular color grading scale used by diamond grading labs is that of the GIA (Gemological Institute of America).

Using this system, color grades are denoted by letters, beginning with D (the highest color grade) and decreasing to Z (the lowest color grade).

GIA refers to stones graded D-F as colorless. In the next group, we find Near Colorless diamonds ranging from G-J in grade. There are three categories of yellow diamonds: Faint Yellow, Very Light Yellow, and Light Yellow. The Faint Yellow stones are graded from K to L. The Very Light Yellow stones are graded from N to R, and the Light Yellow diamonds are graded from S to Z.

Usually, diamonds are graded according to their color by comparing them with benchmark stones (master stones), which correspond to different color grades.

How Is Diamond Clarity Graded?

A diamond’s clarity is determined by examining the stone under magnification as well as with the naked eye to determine whether any visible flaws or inclusions exist.

Numerous factors determine the visibility of inclusions, including their size, position, and color, which can be internal or surface flaws.

Diamonds can have many inclusions, but their clarity grade will remain high if they can only be seen with a microscope. On the other hand, a diamond can have few inclusions, but if they are prominent and visible to the naked eye, the clarity will be low. Additionally, inclusions located centrally on the stone have a more significant clarity impact than flaws on the sides.

According to the GIA, diamond clarity grades range from IF (Internally Flawless), FL (Flawless), VVS (Very Very Slightly Included), VS (Very Slightly Included), SI (Slightly Included) to I (Included).

In practice, these grades are further divided into finer grades by adding numbers, so IF, FL, VVS1, VVS2, VS1, VS2, SI1, SI2, I1, I2, and I3 are the grades that are further divided into finer grades.

How Is Diamond Cut Graded?

A diamond’s cut is graded by comparing its proportions to a set of standards.

These benchmarks are ideal diamond proportions that enhance a stone’s brilliance and sparkle.

A cut of a round diamond is usually graded according to its depth and its table diameter expressed as percentages of its girdle (its widest edge).

Round cuts are graded by the GIA on a scale from Excellent to Very Good, Good to Fair, and Poor to Poor.

Other grading labs have scales with slightly different names, but their logic is the same.

Brilliant cuts (such as round cuts) with higher grades will have greater brilliance, whereas lower-graded cuts will appear less brilliant.

How Is Diamond Carat Calculated?

Carat is a unit of weight; one carat equals 0.2 grams or 200 milligrams.

For example, a 0.5-gram diamond has a carat weight of 2.5 carats. You can find out the carat weight of a diamond by weighing it in grams and then dividing it by 0.2. You can convert the carat weight of a diamond to grams by multiplying by 0.2. For example, a 1.5-carat diamond weighs 0.3 grams or 300 milligrams.

Due to the rarity of bigger diamonds, they are exponentially more expensive per carat than smaller ones.

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