Where a diamond has been assessed by a laboratory it is termed a certificated or certified stone. The codes for the different laboratories used are as follows:

Code:	Laboratory:	Code:	Laboratory:
ADL	Antwerp Diamond Laboratory	GIA	Gemological Institute of America
AGA	American Gem Apraisal Laboratories	GII	National Gemological Institue of Israel
CIB	CIBJO (Europe)	GIL	Gem Information Laboratory
CSA	Jewellery Council of South Africa	GTL	Gem Testing Laboratory of Great Britain
DGL	Diamond Grading Laboratories (London)	NGL	Northern Gemmological Laboratories (UK)
EGI	European Gemmological Institute (Antwerp)	HRD	Diamond High Council (Antwerp)
EGL	European Gemmological Institute (Antwerp & London)	HRG	Heinz R Gartner, DGemG, FGA (Germany)
PNF	P N Ferstenberg Pbv A	IGI	International Gemmological Institute (Antwerp)
GAG	Gesellschaft fur Angewandte Gemmologie	PSL	Precious Stone Laboratory (London)
GAN	Gemological Institute of Antwerp	VPT	Verena Pagel-Theisen, DGemG FGA (Germany)
		WG	Werner Galia, DGem, (Germany)

We sell diamonds issued with a GIA, AGS or HRD certificates, but other certificates may be available on request.

Certified Diamond Reports provide this information:

G.I.A. The Gemological Institute of America

GIA is the industry standard for grading. Certificates provide Shape Measurements, Weight Depth Percentage Table Percentage Girdle Thickness Culet Size Polish Symmetry Clarity Grade Color Grade Fluorescence Comments about Diamond Plot of Internal and External Inclusions New cut grade information GIA Grade Cut

 

A.G.S. - American Gem Society

The A.G.S. gemological laboratory is equal to or more strict than G.I.A. AGS quality reports are most often used by diamond cutters who wish to confirm near ideal or ideal cut diamonds. The A.G.S. grading laboratory director is Peter Yantzer, past founding director of G.I.A.'s Gem Trade Laboratory. The A.G.S. was founded by Robert Shipley the founder of G.I.A. A.G.S.. Diamond Quality Reports provides this information:
Description Shape and Cut Weight Measurements Depth Percentage Pavilion Depth Percentage Table Percentage Crown Angle Crown Height Percentage Pavilion Angle Culet Size	Girdle Thickness Polish/Symmetry Clarity Grade Color Grade Cut Grade Fluorescence Comments about Diamond Plot of Internal and External Inclusions

HRD Laboratory Hoge Raad voor Diamant

The Diamond High Council: H.R.D. Certified Diamond Reports provide:
Shape and Cut Measurements Weight Proportions Girdle Percentage Table Percentage Crown Percentage Pavilion Percentage	Girdle Thickness Culet Size Finish Clarity Grade Color Grade Fluorescence Comments about Diamond Plot of Internal and External Inclusions

E.G.L. - The European Gemological Laboratory:

E.G.L. provides a detail diamond report. The E.G.L. certification does provide more proportion information than the G.I.A. diamond report by including the important pavilion and crown angles in their diamond report. Be aware that plots of internal and external blemishes on E.G.L. certifications are much less detailed than G.I.A. or A.G.S. quality reports. Many diamonds under one carat in size are certified by E.G.L. due to the benefit of lower cost and faster service. E.G.L. also provides a economically priced miniature version of its full certification. E.G.L. Certified Diamond Reports provide this information:
Shape and Cut Measurements Weight Depth Percentage Table Percentage Crown Angle Pavilion Angle Girdle Thickness Culet Size	Polish Symmetry Clarity Grade Color Grade Fluorescence Comments about Diamond Plot of Internal and External Inclusions

Certificate Abreviations Girdle EXTN, ET, XT, EXN = Extremely Thin VTN, VT, VETN = Very Thin T, TN, TH = Thin M, ME, MD = Medium STK, ST, SLTK, SLTH = Slightly Thick T, TK, TH = Thick VTK, VTH, VETK, VET = Very Thick ET, EXTK, XT, XTK = Extremely Thick F, FA, FAC = Faceted S, SM = Smooth P, PO = Polished Fluorescence N, NO, NON, - No Fluorescence F, FB, FT, FA, - Faint or Faint Blue Fluorescence SL, SLB, SLT, - Slight Fluorescence M, MO, ME, MD - Medium or Moderate Fluorescence S, ST, STB, STG, - Strong Fluorescence E, EX, EXB, EF, - Extreme Fluorescence Culet N, NO, NON, - No Culet P, PO, PN, PNT, - Pointed VS, VSM, VRSM, - Very Small S, SM, SML, - Small M, ME, MD, MM, - Medium L, LA, LG, - Large VL, VLG, VRLG, - Very Large EL, EX, EXLG, - Extremely Large Symmetry EX or E - Excellent, Flawless at 10X power VG or VGD - Very Good, Extremely difficult to locate under 10X power GD, GO, G - Good, Very diffucult to see under 10X magnification F, FR, FA - Fair, Noticable under 10X power PR, PO, P - Poor, Easy to see under 10X / Visible to unaided eye VP, VE, - Very Poor, Relatively easy to see with the unaided eye EP - Extremely Poor, Obvious to see with unaided eye Polish EX or E - Excellent,  Flawless at 10 power VG or VGD - Very Good, Extremely difficult to locate under 10 power GD, GO, G - Good, Very difficult to see under 10 power F, FR, FA -  Fair, Noticeable under 10 power PR, PO, P -  Poor, Easy to see under 10X / Visible to unaided eye VP, VE, -  Very Poor, Relatively easy to see with the unaided eye EP -  Extremely Poor, Obvious to see with unaided eye Characteristics - External Scratches are usually fine surface lines that can be polished away. If you have a scratched diamond, we will be pleased to estimate for polishing. Nicks are areas where a portion of the diamond has chipped away. Small nicks are sometimes repaired by polishing them to create an extra facet. Pits are holes in a diamond's surface. Some pits aren't noticeable, but a pit on the diamond's table facet is more likely to be visible, and can affect the diamond's clarity grade. A natural is a portion of the diamond's original surface that hasn't been polished. Naturals are sometimes left along a diamond's girdle if doing so allows the cutter to produce a larger cut stone. Naturals don't normally impact the diamond's clarity grade if they are confined to the girdle. A trigon is a natural that looks like a small triangle, or triangles within triangles see image to left. Polishing lines are sometimes left over from the cutting and polishing process and are a sign that the makers are cutting corners to reduce costs. Extra facets are created to remove blemishes and can have a detrimental effect on the diamond's appearance and value. Characteristics - Internal Pinpoints Pinpoints are tiny light or dark crystals that appear by themselves or in clusters. Larger clusters of minute pinpoints can create a hazy area, called a cloud, which can detract from a diamond's clarity. Laser Lines Laser lines are not a natural inclusion. These vapor- like trails are left behind when lasers are used to remove dark inclusions from the diamond. The machine-made trails look like tiny strands of thread that begin at the diamond's surface and stretch inward to the point where the inclusion was removed. Feathers Feathers are cracks within a stone that resemble feathers. Small feathers do not usually affect a diamond's durability unless they penetrate the surface on the top of the stone. A feather that breaks through the surface in a vulnerable area increases the risk of breaking the stone. Girdle Fringes, Bearding Girdle fringes, or bearding, are stress hair-like lines that can occur around the girdle during the cutting process. Minimal bearding is usually not a problem, but extensive fringing can often be polished away or removed by recutting the diamond. Cleavage A cleavage is a straight crack with no feathering. A cleavage has the potential to split the diamond apart if it is hit at the correct angle. Graining Lines, Growth Lines Graining lines are created by irregular crystallization that takes place when the diamond is formed. Colorless graining lines do not usually affect diamond clarity unless they are present in large masses. White or colored graining lines can lower a diamond's clarity grade. Inclusions are like fingerprints, a characteristic that gives us all a special signature. Getting to know your diamond inside and out makes the stone a more personal possession.

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