The GIA and AGS Clarity Grading Scale

Flawless (FL)
No blemishes or inclusions visible at 10X magnification. Investment grade. Rarely used in jewelry. Everyday wear can lower a diamond’s clarity range from Flawless to Internally Flawless if it gets scratched. Priced much higher than any other grade.

Internally Flawless (IF)
No inclusions and only insignificant blemishes on the diamonds surface  (such as tiny pits or scratches that can easily be removed by polishing).  Also priced much higher than other grades.

Very Very Slight Inclusions (VVS1 and VVS2)
Trained diamond graders have to view a diamond under 10X magnification (sometimes from different angles) to find the inclusions. Inclusions are so small that the average person will not be able to find them. Priced higher because the supply is very limited.

Very Slight Inclusions (VS1)
Minor inclusions that are difficult to see under 10X magnification. Inclusions range from small crystals, pinpoints, clouds, and feathers. An exceptional choice for engagement rings.

Very Slight Inclusions (VS2)
Minor inclusions that are difficult to see under 10X magnification. The same type of inclusions as VS1, but are more numerous, larger and slightly easier to see. An exceptional choice for engagement rings.

Slight Inclusions (SI1) 
Even though this is the seventh clarity grade from the the beginning of the scale, this is an attractive diamond. If one were to view it face-up with your naked eye, you normally will not see any inclusions. Under 10X magnification, you will notice clouds, crystals, or feathers. There is significant cost savings in purchasing a SI1 clarity that can be used towards a larger diamond or a higher color grade.

Slight Inclusions (SI2)
The same type of inclusions as SI1, but are more numerous, larger, and easier to see. Inclusions may be visible when a diamond is viewed face-up with the naked eye. Inclusions in larger diamonds and emerald cuts may be easier to see because of the larger facets. Sometimes you can see the inclusions when you view the diamond through the pavilion (bottom). Still a good choice for an engagement ring, especially when combined with a high cut rating.

Imperfect (I1)
Inclusions are obvious under 10X magnification and may be visible to the naked eye when viewed face-up. May be a good choice if you are on a limited budget. An I1 clarity that is well cut can often look better than a poorly cut SI1.

Imperfect (I2)
Inclusions are easily visible to the naked eye and may affect the durability of the diamond. May appear cloudy and lifeless. This grade is usually used in discount jewelry.

Imperfect (I3)
Often look shattered. Diamonds of this clarity grade often have a muddy or whitish appearance because they are so full of crystals. Very little luster or sparkle. Some diamonds in this range are actually industrial quality and should not be used for jewelry.

GIA and AGS Clarity Terms

Each GIA and AGS grading certificate notes the clarity terms that are visible within the diamond being graded. Some characteristics are minor and should not influence your decision. Some are major and should be avoided in all instances.

Inclusions  (under the diamond surface) 

Bruise - a small area of impact (concussion) that may create root-like lines within a diamond. Usually caused by a quick, sharp blow.

Cavity – an indentation that breaks the diamonds surface. Usually caused by a knot or included crystal that was pulled out during the polishing process. Also may be caused by a cleavage or a sharp blow.   A cavity can turn dark and unsightly with everyday wear as it traps oil and dirt.

Chip – a shallow opening on the surface that usually happens as a result of an impact. Usually occurs after a diamond has been been cut and polished. Most chips occur on the diamond girdle during everyday wear if the diamond is hit hard. Do not consider a diamond with an extremely thin girdle (noted on the diamond certificate) as it is prone to chipping.

Cleavage – a diamond can cleave if it sustains a strong blow. AVOID a diamond if cleavage is noted on a diamond certificate. A cleavage crack compromises a diamonds durability. It can expand and cause a diamond to break with daily wear.

Cloud –  a very common occurrence in diamonds. Most clouds are made up of a cluster of pinpoint crystals that are too tiny to see individually under 10 power magnification. Larger clouds (lower clarity grades) may make a diamond appear hazy or milky because they interfere with the reflection of light within the diamond.

Crystal – commonly seen in diamonds. Can be any size or color and occur alone or in groups. Minute crystals that look like small specks under 10 power magnification are called pinpoints.  When they are totally enclosed within a diamond they are called "included crystals". Some people call them "bubbles" which is misleading and should not be used. The larger and more obvious the crystals are, the more it will affect the clarity grade.

Feather –  A general term for any break, crack, or tiny fracture in a diamond.  Normally you don’t have to be concerned about feathers if they are small. Large feathers may be visible to the naked eye and reflect light at certain angles. They may worsen over time and be should be avoided because they can cause a stone to break. If the feather extends to the outside of a diamond it can weaken the diamond.  I don't recommend purchasing a diamond if the feather extends to the outside surface.

Grain Center – a small concentrated area of crystal growth distortion that usually appears as pinpoints. Not visible from all directions – grain centers may disappear and reappear as you turn a diamond.

Indented Natural – a tiny indented edge of the original rough diamond crystal that is left on the surface after it has been polished. A cutter will try to position an indented natural near the girdle or on the pavilion so that it is not noticeable. It can be removed, but this will result in a reduction of weight. An indented natural is a sign of good cutting because the diamond cutter retains as much of the original weight as possible.

Internal Graining – lies beneath the surface of a diamond and can affect the clarity grade – especially in higher grade diamonds. Internal graining appears as parallel lines that are colorless, tinted off-white, or light color shades.

Knot – included crystals that are left exposed on the surface of a diamond by polishing. Knots can severely reduce the value of a diamond and affect its durability. This is definitely an inclusion you will want to stay away from.

Laser Drill Hole – a treatment that is used to remove dark inclusions within a diamond. A laser beam is used to drill a narrow hole to a dark inclusion which is then dissolved or bleached by acid. With magnification, a skilled jeweler can detect laser drilling. A well respected laboratory will disclose laser treatment on the certificate. Laser drilling reduces the price by 10-35% depending on how many inclusions have been drilled in the diamond. Laser drilling should be disclosed by the jeweler selling the diamond, though many times it is not. This is another reason you must buy a diamond with a certificate from a respected diamond grading laboratory.

Needle – long thin crystals that resemble a rod. Can appear bright, white, or dark.

Pinpoint – the most common inclusion found in diamonds. Pinpoints are tiny minute crystals (usually white in color) that are found inside a diamond. Most pinpoint inclusions are not visible to the naked eye and do not affect the clarity grade unless it is a VVS or higher.

Twinning Wisp – a series of pinpoints, clouds, or crystals that occurs on a diamond's growth plane. This inclusion may appear to look like a ripple.

Blemishes (on the diamond surface)

Abrasion –  tiny nicks that occur along facet edges that produce white, fuzzy lines instead of crisp facet edges. Abrasions usually occur from carelessly storing loose diamonds together, but can happen with everyday wear over time.

Burn Mark – usually occurs when a diamond is polished too rapidly. Heat caused by friction can build up causing the diamonds surface to be burnt.

Extra Facet – Can appear anywhere on a diamond, but are usually found near the girdle. Extra facets are usually added to polish away a surface blemish as it is being cut. It does not affect the clarity grade if it is on the pavilion and cannot be seen at 10 power magnification.

Natural – part of the original surface of a diamond that is left unpolished. It  does not affect the clarity grade if the natural is confined to the girdle and does not distort the shape of the diamond.

Nick – minor surface chips caused by hard use and wear. Occur most often along the girdle.

Pit – a tiny cavity that looks like a white dot. Usually occurs when pinpoint inclusions are pulled away from the diamond during polishing. Most often found by the girdle or culet (bottom point of a diamond).

Polish Lines - tiny parallel lines left by polishing. Very common – even on high color and clarity diamonds.

Scratch – in order for a diamond to be scratched, it must come in contact with another diamond. Be careful that your engagement diamond does not come in contact with other diamonds.

Surface Graining – A natural irregularity of the diamond crystal. Surface graining appears as a line traveling across one of more facets. You can see it with magnification. It looks like they are polishing lines, but they cross facet junctions while polishing lines don’t.