The color of an M. Lemp Jewelers diamond is caused by light passing through chemical impurities and/or inclusions in the stone’s crystalline structure. It’s these inclusions that alter the light pattern that gets absorbed so that color is visible to the human eye. The most common color that diamonds are found in is yellow. The amount of yellow hue is graded according to a scale which ranks the lack of color with the highest letter grades and ranges from D (colorless) to Z (heavy yellow). Diamonds whose colors are beyond Z are denoted as “fancy” diamonds and are graded using their own scale and terminology. The purer and more intense the color, the rarer and more valuable the diamond is.