• Solid mineral inclusions of various colors: green – olivine, diopside; red – garnet; black – sulfides or ilmenite; and colorless (diamond inclusion). Other minerals are present more rarely. In diamond grading, the size, color, position, and repeated reflection of the inclusions matter rather than their composition.
• Pinpoint- a very small inclusion, which usually appears as a point under the loupe. Some specimens contain groups of pinpoints.
• Needle - a long thin crystal - acicular inclusion.
• Cloud - hazy or milky zone consisting of a great number of tiny inclusions.
• Cracks (International systems often use the term "feather")
  • Parallel to cleavage. These cracks are parallel to each other and are orientated in directions of cleavage. They can occur inside a stone and not open to the surface. Under mechanic stress, a stone can be cracked up along the cleavage direction.
  • Cracks resulting from thermal gradient during crystal growth. These cracks may have a chaotic distribution.
  • Tensor cracks. These cracks occur near solid mineral inclusions and originate due to the difference in the coefficient of thermal expansion between the inclusions and diamond. They typically have elongated or disc-like shape
  • Cracks of mixed types are noted.
• Structural features . appear during diamond crystal growth. Not being a damage or an extraneous object, such features are referred to as structural defects. The defects of this type are often described with such terms as graining, growth lines, twinning wisps and twinning planes. These features may appear as turbid zones, lines, bands, and planes. They can be milky or colored and sometimes influence the total transparency of a stone.
• Grain center - a small area of concentrated distortion of crystal structure; usually is accompanied by pinpoint inclusions.
• Nick- a small and shallow pit typically occurring on the girdle edge. Some nicks may have a greater size.
• Cavity - a large three-dimensional opening on the surface of a polished diamond.
• Bearded girdle("bearding") - microcracks extending from the girdle into the stone.
• Bruise - a deformation zone on the diamond surface caused by a blow.
• Crystal in crystal - a diamond microcrystal inclusion in polished diamond.
• Knot - a diamond inclusion standing out against the surface of the polished diamond.
• Indented natural - a natural crystal face which is deepened into the stone.
• Laser drill hole - a laser-drilled needle-shaped hole, which appears as a pit on the diamond surface.

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• Abrasion - smoothing of edges and vertexes mainly caused by careless cutting. Microcracks orientated along the edges are often perceived as white lines rather than sharp edges.
• Extra facet - a facet present in addition to those required by a given cutting style and which does not fit the symmetry pattern.
• Natural - part of the original natural diamond surface which is left on the polished stone after cutting.
• Pit - microopening which often appears as a white point.
• Polish lines - thin parallel lines left after polishing; thin parallel ridges within one facet caused by the irregularity of the crystal structure; small parallel polished trenches formed by the cutting disk surface.
• Polishing marks - hazy areas of the stone surface caused by excess heating (superheating) during cutting or polishing.
• Rough girdle - feathery or cavernous girdle surface, often with microcracks..
• Scratch - a linear trench, which typically appears as a thin white line (curved or straight).
• Surface graining – - defects and distortions of the diamond crystal structure which reach the surface of the stone and often cross facet junctions.

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Symbol	GIA Clarity Grades	Short Description
IF	INTERNALLY FLAWLESS	No inclusions, and only insignificant blemishes.
VVS1 VVS2	VERY, VERY SMALL INCLUSIONS	Minute inclusions that are difficult to see. In VVS1, they are extremely difficult to see, visible only from pavilion, or small and shallow enough to be removed easily by repolishing. In VVS2, inclusions are still very difficult to see. Typical inclusions: scattered pinpoints, faint clouds, slightly bearded girdles, internal graining, and tiny feathers, chips, and bruises.
VS1 VS2	VERY SMALL INCLUSIONS	Minor inclusions ranging from difficult to somewhat easy to see. Typical inclusions: small included crystals and feathers, distinct clouds, and groups of pinpoints.
SI1 SI2	SMALL INCLUSIONS	Noticeable inclusions that are easy (S1I) or very easy (S2I) to see. Inclusions are often centrally located and noticed immediately; that may be eye-visible. Typical inclusions: included crystals, clouds, feathers.
I1 I2 I3	IMPERFECT	Obvious inclusions that are often easily eye-visible face-up; in I3, they may threaten durability. Typical inclusions: large included crystals and feathers.

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• Preparation (cleaning) of a stone.
• Face-up examination at 10x magnification. Corrected optics should be applied. Dark field illumination is recommended for determining internal features and reflected light - for external features.
• Approximate evaluation of the inclusions. Clarity range is usually determined at this stage.
• Careful profile examination: around the girdle, from different sides (through the crown and pavilion facets). All the features are noted, including size, number, nature, color, and relief.
• Face-up examination for the evaluation of the total clarity of a stone. If a microscope is used for the study, it is recommended to examine dark-looking inclusions with a loupe. If the detection of an inclusion takes much time, VVS category is assigned. VS - inclusions are easily detected; SI - inclusions are detected immediately; I - inclusions are obvious and are visible to the unaided eye.
• · Differentiation between VVS1 and VVS2; VS1 and VS2; SI1 and SI2; I1, I2 and I3.

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• To distinguish an internal feature from a dust particle, which can be left on the surface, the stone should be slightly tilted or rotated. During the rotation, inclusions move less than dust and external features. Another method is to catch a reflection from the facet which supposedly contains the observed feature.
• For observation of light inclusions, it is convenient to hold a stone so that the inclusion is seen against the dark background (conversely, dark inclusion - against the light background)..
• Minor internal features (points, invisible through the table) can be detected by holding the diamond at the girdle with tweezers and orientating it so that the eye direction is perpendicular to the main pavilion facets.
• When internal features are searched, one should be sure that the diamond bulk is thoroughly examined. The thorough examination is attained by rotating the stone and successive focusing sight on different zones. An expert is free to choose the order of examination most convenient to him.

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The characteristic features of a graded stone should be indicated on the crown and pavilion identity diagrams as well as in the worksheet or certificate. The features are recorded in order to identify the stone, to fix its present state, and to justify its grading. Only those features are noted on which the grades, identification, and description are based. The marks on the diagram usually denote the location of the features, but may not show their actual dimensions.

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External features
Extra facet		EF
Natural		N
Abroaded Culet		Abr
Abrasion		Abr
Nick		Nk
Pit
Polish lines		Pl
Scratch		S
Surface Graining		Sgr
Bearded Girdle		BG
Internal features
Bruise		Br
Chip small		Ch
Chip large		Ch
Cloud		Cld
Feather		Ftr
Included crystal		Xtl
Internal graining		IntGr
Knot		K
Laser drill hole		LDN
Pinpoint		Pp
Twinning wisp		W
Grain center		CrCnt

• The cutting style shown by the diagram should correspond to that of a graded stone.
• Naturals bounded by the girdle and all inclusions are marked in the crown diagram, except for those reaching the pavilion surface and those visible only through the pavilion facets.
• External defects and extra facets are indicated on the sides of the diagram where these features actually occur.
• The inclusions reaching both crown and pavilion surfaces should be shown on both diagrams.
• Color of the marks: extra facets - black solid lines; mounting - black hatching; external defects - green; cavities, large nicks, indented naturals, knots, and laser drill holes - red and green; and other inclusions - red.
• It is recommended to begin with the defects closest to the girdle.
• Some features may be omitted in copies prepared for a client (certificates) not to overload the diagram.
• The most obvious (deciding) feature is usually marked in the upper part of the diagram (at "twelve o'clock").

An example diagram with commonly acceptable symbols is shown in figure.