CLARITY GRADING SCALE

The clarity of a diamond depends on how clear or clean it is — how free it is of blemishes and inclusions, when viewed with the naked eye and with a 10X loupe, or magnifier. Let's define our terms.

BLEMISHES: Imperfections on the outside of a diamond

Chip: A little piece missing, caused by wear or the cutting process. Scratch: A line or abrasion.

Fracture: A crack on the diamond's surface.
Polishing lines: Fine lines on the stone's surface formed during the polishing stage.

Natural: An unpolished part of the diamond.

Extra facets: Additional polished surfaces that shouldn't be there and spoil the symmetry of a diamond.

Bearding: Very small fractures on an edge of the diamond.

INCLUSIONS: Imperfections inside a diamond.

Carbon: Black spots inside a stone.

Feather: Internal cracking.

Crystal: White spots inside a stone.

Pinpoint: Tiny spots, smaller than a crystal.

Cloud: A group of pinpoints, which may give the impression of a single large inclusion.

Loupe: (pronounced loop) a small magnifying glass used to view gemstones. Any good jeweler will let you use one, and show you how. They should be 10X, or 10-power magnification, and the housing around the lens should be black so as not to distort the color of the stone. The Federal Trade Commission requires diamond grading to be done with a 10X magnifier, and any flaw that can't be seen under 10X magnification is considered nonexistent.

Here are the CLARITY GRADES OF DIAMONDS, as established by the Gemological Institute of America (GIA):

FLAWLESS: Free from inclusions and blemishes when viewed under 10X magnification. Very rare and very expensive.

INTERNALLY FLAWLESS: Free from inclusions; may have slight blemishes when viewed under 10X magnification. Also very rare and very expensive.

VVS1 AND VVS2 (VERY, VERY SLIGHTLY INCLUDED): Has minute inclusions or blemishes the size of a pinpoint when viewed under 10X magnification. Rare and expensive.

VS1 AND VS2 (VERY SLIGHTLY INCLUDED): Has inclusions or blemishes smaller than a grain of salt when viewed under 10X magnification. No carbon, fractures or breaks. High quality.

SI1 (SLIGHTLY INCLUDED): Has inclusions or blemishes larger than a grain of salt when viewed under 10X magnification, and these inclusions can be carbon or fractures. Almost all SI1 diamonds are eye-clean, which means the flaws can't be seen with the naked eye. Good quality.

SI2 (SLIGHTLY INCLUDED): Has inclusions or blemishes larger than a grain of salt when viewed under 10X magnification, and some of these flaws may be visible to the naked eye. Borderline diamond.

I1 (IMPERFECT): Has inclusions and blemishes visible to the naked eye. Commercial grade. Not my taste!

I2 (IMPERFECT): Has inclusions and blemishes visible to the naked eye that can make as much as one-fourth of the diamond appear cloudy and lifeless. Same as above.

I3 (IMPERFECT): Has many, many inclusions and blemishes visible to the naked eye. Not a pretty diamond. Very little luster or sparkle. Bottom of the barrel.

Suggestion:
Aim for an SI1 diamond. Many people unwittingly buy I1 and I2 stones, but if you shop carefully you can buy an SI1 stone for the same price that most I2 stones are sold for.

Clarity grading a diamond is easier than learning your ABC’s. There are two main categories to be concerned with: The diamond with inclusions¹ and blemishes² we can see with our own eyes, category I, and those that appear to be “eye clean,” category II. Once we’ve determined which category a diamond falls in, we can break it down into sub-categories.

Category I: The Imperfects - SI2, I1, I2, I3 (a.k.a., River Rocks, Bluff Diamonds, Commercial Grade and Drill Bit Dodgers) While the easiest way to determine the clarity grade of a diamond is just to ask the seller, this assumes he’s telling you the truth. But since these four grades are the bottom of the barrel, You will meet very few vendors who will brag about how bad their diamonds are. The vendor is also aware that even if you’re farsighted and they could misrepresent them, it’s not very likely your fiancé or independent appraiser will fall into the same trap. Therefore, if a jeweler tells you your diamond is an SI2, I1, I2 or I3; know you’ve gone as low as you can go. These grades tend to be popular with people who want size over quality. In pictures 1, 2, 3, 4, 5, 6, 7, 8 and 9 you can see some great examples of the kind of damage you can expect to find in these flawed rocks.

Category II: “Eye Cleans”
A. The Investments – Flawless, Internally Flawless, VVS1, VVS2 (a.k.a., Bentleys, Rolls, Safe Deposit Rocks)
When you look at pictures 10A, 10B, 10C and 10D, you’d swear you’re looking at the same diamond, but you’re not! You’re looking at four different round diamonds viewed under 10X magnification. Which one is the Flawless, which one is Internally Flawless and which ones are the VVS? If all four grades look identical under magnification to the average bear, or are indistinguishable to gemologists without the aid of a loupe³ or microscope, then don’t worry about it. What makes these rocks distinguishable from the rocks in the first category is their LACK of inclusions, not the presence of any.

B. The Street Legals – VS1, VS2 - appropriately named due to being the highest grade recommended to wear or mount into jewelry (a.k.a., Mercedes, The Benz, The Lambs [short for Lamborghini]). This category is my favorite for a variety of reasons; not only are they practically microscope clean and totally “eye clean,” they allow the purchaser to get good to exceptional quality without sacrificing too much on size. In pictures 11A and 11B the diamonds appear flawless, until we zoom in (11C) and easily find pinpoints and small crystals (smaller than a grain of salt) caught in the diamond’s lattice.

C. The Slights – SI1 – named because they have slight problems but nothing that will effect the beauty. The SI1’s are easy to grade. They always look great to the eye, but the minute you pick up a loupe even a novice can locate the imperfections. Because all the inclusions are typically larger than a grain of salt but small enough to stay under the “eye clean” radar, SI1’s become a popular choice for maximum size but above average quality. In pictures 12A, 12B 12C and 12D we see classic crystals, feathers, abraded girdles and pinpoints one might expect to see in an SI1.

¹Inclusions – imperfections inside a diamond (carbon, feather, crystal, pinpoint, cloud)
² Blemishes – imperfection on the outside of a diamond (chip, scratch, fracture, polishing lines) 
³Loupe – a small magnifying glass used to view gemstones.