The date of the report is the date when analyses are completed and when the report is issued.
Unique reference number
The Laboratoire Français de Gemmologie gives a unique reference number to each item submitted for examination. This number identifies the item at each stage of analysis. When a stone has already been seen and comes back after a re-cutting or a preliminary examination, a new number is assigned to it.
Shape, cut and dimensions
The shape, cut and dimensions describe the external appearance of the stone. When you submit a piece of jewellery with several stones, or lots, we indicate the diametrical variation of the lot.
The weight (mass) of the stone is shown in carat weight with a precision of two decimals. The third 9 after the decimal point is rounded up to the nearest hundredth. For instance: 0.9990 will be shown as 1.00 carat, 0.9989 shown as 0.99 carat. If it is a jewel set with stones, then it is weighed in grams.
The cut grade is based on strict standards combining information on proportions, symmetry, polish and thickness of the girdle. The cut grades range from: Excellent – Very good – Good – Fair – Poor.
Poli & symmetry
The Polish / symmetry grades range from : Excellent – Very good – Good – Fair – Poor. They are essential to cut grading.
The fluorescence grades range from : None – Faint – Medium – Strong – Very strong.
It is in the comments section that the LFG provides additional information related to treatments. For example the HP-HT treatment of your stone, or laser drilling.