Unit of diamond weight. 1 carat = 0.2 grams. Not to be confused with karat (gold purity).

How well the diamond's facets interact with light. The most critical factor for brilliance. GIA grades: Excellent, Very Good, Good, Fair, Poor.

Graded D (colorless) to Z (yellow/brown). D–F: colorless; G–J: near-colorless; K+: visible warmth. Same scale for natural and lab-grown.

Absence of inclusions/blemishes. FL → IF → VVS1/VVS2 → VS1/VS2 → SI1/SI2 → I1–I3. VS2 is the recommended sweet spot for value.

Gemological Institute of America. World's most respected grading lab. A GIA certificate is the gold standard for natural diamonds.

International Gemological Institute. The preferred certifier for lab-grown diamonds. IGI grading for lab stones is accurate and widely accepted.

Chemical Vapor Deposition. One of two main methods to grow lab diamonds. Grows diamonds layer by layer in a chamber using carbon gas.

High Pressure High Temperature. Second lab-growing method replicating conditions deep in the Earth. Both CVD and HPHT produce real diamonds.

A diamond's tendency to glow blue under UV light. Strong fluorescence in D–F diamonds can cause haziness — generally reduces price.

Angular Spectrum Evaluation Tool. Optical device showing how a diamond returns light. Used by Whiteflash to verify ideal cut performance.

Industry-standard wholesale diamond price list published weekly. Retail prices derive from Rapaport with individual retailer markups.

Diamond whose inclusions are invisible to the unaided eye at arm's length. Most VS2 and many SI1 round brilliants are eye-clean.

Small accent diamonds (typically under 0.2ct) used to decorate ring settings, halos, and pavé bands.

Setting style where small diamonds are set closely together across the band surface, creating a continuous sparkle effect.

Pattern visible in ideal-cut round diamonds: 8 hearts from below, 8 arrows from above. Indicates perfect optical symmetry.