As the size of a diamond increases, so does its rarity and value. To determine its size, diamonds are measured in either carats or points. One carat is equal to 100 points, or 200 milligrams.
Every diamond contains inclusions, which are simply slight imperfections in the makeup and clarity of the stone. In general, lower amounts of inclusions equal higher value for a diamond. Diamonds with inclusions that are visible to the naked eye are called level I clarity. These are subdivided into I1 clarity, which include one or two very small discernible inclusions, I2 clarity, which has a moderate amount of inclusions, or I3, which feature heavy inclusion. Level SI2 clarity diamonds and better represent stones that feature inclusions that are invisible without magnification. FL represents diamonds that are internally flawless with or without magnification, which are incredibly rare and valuable.
Diamonds that are rated D, E, or F are considered to be “colorless.” Those rated G-J are rated “near colorless”. The letters on the scale go down to Z. As the scale lowers, the color quality of the diamond also follows suit. Most quality diamonds are rated to be level J or higher.
The cut of a diamond is judged based on its depth, table, polish, symmetry, girdle, and culet. Depth refers to the measurement of a diamond from its top to bottom, the table refers to the flattened top of the stone, the polish refers to the appearance of its luster, symmetry refers to its uniformity and shape, girdle represents the border between a jewel’s crown and pavilion, and finally the culet refers to the apex located at the bottom of the jewel. All of these factors contribute to determining the value and beauty of a gem. The best cut of a diamond is an “ideal cut”, which is a diamond that has been shaped to fit within specific parameters for the most attractive shape and appearance.