The certificate is the identity card of your diamond. It certifies of the laser engraved authentication number on the rounder and is essential for stones over 0.50 ct. For those of lesser weight, a gemologist’s certificate is sufficient. The reputation of a laboratory stands on its rigor and impartiality in the analysis of a stone.
Globally recognized laboratories:
-
GIA (Gemological Institute of America)
-
HRD (Hoge Raad Voor Diamond)
-
IGI (International Gemological Institute)
-
AGS Laboratories (American Gem Society)
Additional Grading Information
-
Finish
-
Polish
-
Symmetry
-
Inclusions are considered according to their nature, size, position and visibility.
Stones treated, heated or irradiated to remove inclusions or improve the color lose from 30% to 80% of their value.
We recommend to not consider these stones:
-
Clarity Enhanced: Modified Purity
-
Color Enhanced: Modified color
-
Laser Drill Hole: Laser Hole
"Minor" inclusions
Cld) Cloud - Cloud: nebula / milky stain. Set of crystals
(K) Knot - Knot: Diamond Crystal
(Pp) Pinpoint - Cristallite: Small point in the stone
(Ndl) Needle - Needle: Long thin crystal
(Xtl) Included Crystal - Crystal Included: Small crystal included
(IndN) Indented Natural - Inlaid Crude Indicator: Unpolished Part
Indented Natural
Grain Center
Inclusions difficult to observe
(IntGr) Internal Graining - Internal Structural Deformation Line : A sign of crystalline growth. "Stress" during the formation of the stone
(SGr) Surface Graining - Line of internal deformation which manifests itself on the surface: Disturbance of the crystalline structure on the surface
(GrCnt) Grain Center - Center of Internal Structural Deformation: Transparent inclusion like internal deformation lines
Cloud of microcrystals
Inclusions that require vigilance
(Br) Bruise - Shock trace: shock on the surface of the diamond
(Cv) Cavity - Cavity: Hollow on the stone
(Ch) Chip - Chip: Missing shine on the edge of the girdle
(Ftr) Feather - Feather: Breakage inside or from the inside to the outside
(Clv) Cleavage - Cleavage: Break in an entire plane inside the diamond.
(W) Twinning Wisp - Veil: Mixture of inclusions, crystallite, feathers, crystals included and clouds
(LDH) Laser Drill Hole - Laser Hole: Small tube made by laser beam
Black cristal
Burn mark
Feather
Surface characteristics
(Abr) Abrasion marks: Small white specks on the facet edges
(EF) Extra Facet - Extra facet: Facet placed out of symmetry
(N) Natural - Raw (or "naive") witness: Part of the original unpolished crystal
Pit - Sting: Light hollow, can look like a white point
(PL) Polish - Lines: Small parallel lines due to bad polishing
(Brm) Burn Mark - Overheating Mark: Nebulous traces due to excessive temperature during polishing or Crystalline structure defects
(S) Scratch - Stripe: Hollow line, may be white
Laser Hole