Every diamond we supply arrives with a report from an independent laboratory, usually the Gemological Institute of America (GIA) or HRD Antwerp, together with the Danelian Certificate. The report is worth reading. It is also worth knowing its limits.
What the report records
Shape and cutting style. Round brilliant, cushion modified brilliant, emerald cut and so on.
Measurements. Length, width and depth in millimetres. Two stones of the same carat weight can have quite different face-up sizes; measurements tell you which.
Carat weight. To the hundredth of a carat.
Colour grade. From D (colourless) down the alphabet. Most of what we sell sits between D and H. Beyond that the differences are visible to a trained eye, and eventually to any eye.
Clarity grade. From Flawless to Included. A plotted diagram shows where the characteristics are. A small inclusion at the edge, hidden by a prong, matters far less than one under the table.
Cut grade (round brilliants only). Excellent, Very Good and so on. This is the grade most people overlook, and the one that most affects how a stone looks.
Fluorescence. A stone’s reaction to ultraviolet light. Usually harmless, sometimes helpful, occasionally not. We will tell you which.
Laser inscription. A microscopic number on the girdle, matching the report. Ask to see it under the loupe.
What the report cannot tell you
Whether the stone is beautiful. Two diamonds with identical grades can differ in the life they show under normal light. That judgement is made in person, by eye, and it is the reason we always sit with clients and their stones before anything is decided.
The Danelian Certificate
Our own certificate accompanies every stone. It records the laboratory report number, the mounting, and our commitment to the piece for as long as you own it.
