The Lumen

Stone Grading Information

Diamonds

Color: Graded from D (colorless) to Z (light color). Grades D through F are considered colorless, making them highly desirable.

Clarity: Ranges from Flawless (FL) to Included (I1 to I3). Common clarity grades are VS1 and VS2, which stand for Very Slightly Included — minor inclusions difficult to see under 10x magnification.

Carat: Refers to the weight of the diamond. One carat is equal to 200 milligrams. Carat weight can significantly influence value, especially when combined with high color and clarity grades.

Cut: Assesses how a diamond's facets interact with light. Excellent cuts provide brilliant sparkle.

Alternative Stones

Non-diamond gemstones such as sapphires, emeralds, and rubies have different grading criteria:

Color: Generally the most important factor. Vivid, highly saturated colors are most prized.

Clarity: While inclusions are more accepted, their nature and location can impact the stone's appearance and value.

Cut: Focuses on enhancing the gemstone's color and brilliance rather than strictly on symmetry or proportion.

Carat: As with diamonds, a higher weight can increase the stone's value, but color and clarity carry more weight in the overall grading.