Internal imperfections of a diamond affecting the clarity grade. Diamonds grow deep in the earth under extreme pressure and temperature; under these conditions, it is rare to find a diamond that is internally flawless.
World Federation of Diamond Bourses
International confederation of diamond bourses. The WFDB imposes strict rules and guidelines for ethical and professional conduct for the diamond trade on an international level.
Yellow Diamond
A coloured diamond with a natural yellow body colour. Yellow must be the predominant colour, but it may be modified by shades of green, orange, or brown. The colour in natural yellow diamonds is created by the presence of nitrogen as an impurity when the diamond is growing. Natural yellow diamonds are common; canary diamonds are however more rare.
Wavy Girdle
Upper-Girdle Facet
Trilliant
Diamond cut or shaped into a triangle, sometimes with curved sides.
Twinning Line
Transparency
Degree to which a diamond transmits light, directly relevant to the cloudiness or haziness of the actual diamond material, and the quality of the crystal. Click here to learn more about transparency and the DCLA Transparency Grading System.
Treated Diamond
Diamonds that are artificially enhanced, to improve either colour or clarity. These treatments fundamentally alter the diamond from its natural state, and therefore need to be fully disclosed. Click here to learn more about treated diamonds.
Trigon
Triangular shaped natural, with very fine triangular concentric lines. Trigons, when present, are a definitive indicator of natural diamonds.