Education

The Modern Cut Grade System (5.43)

GIA's cut grade system is comprised of brightness, fire, scintillation, polish, symmetry and durability.

Diamond’s Containment of Light (5.06)

The design of the modern round brilliant is such that it “contains” the light that enters it as long as possible.

Single and Double Refraction (5.05)

Diamond is singly refractive -- but some gemstones are doubly refractive such as alexandrite, aquamarine, citrine, kunzite, corundum (ruby/sapphire), spinel, tourmaline, moissanite. Light bend as it enters the diamond but...

Refractive Index (5.04)

Diamond is unique in the sense that it has the high refractive index of 2.417.

Designing the Modern Cut (5.03)

Designing the round brilliant cut diamond for optimal light performance. The difference between reflected light and transmitted light.

Measuring Table Size (5.25)

Measuring Table Size (5.25)The most accurate way to measure a table is with a table gauge. This is a small, transparent, plastic ruler that measures in increments of tenths of...