Education

Estimating Pavilion Angle (5.15)

The original preferred pavilion angle of 40.75° corresponds to a pavilion depth percentage of approximately 43%.

Estimating Pavilion Angle (5.15)

The original preferred pavilion angle of 40.75° corresponds to a pavilion depth percentage of approximately 43%.

The Pavilion Main Method (5.14)

Estimating crown angles with the Pavilion Main Method.

The Pavilion Main Method (5.14)

Estimating crown angles with the Pavilion Main Method.

Judging Crown Angles (5.13)

Judging diamond crown angles.

Judging Crown Angles (5.13)

Judging diamond crown angles.

Proportion Analyzers (5.12)

The proportionscope, first designed and manufactured by GIA in 1967, is an instrument that casts a silhouetted image of the diamond It allows us to check the proportions of the...

Proportion Analyzers (5.12)

The proportionscope, first designed and manufactured by GIA in 1967, is an instrument that casts a silhouetted image of the diamond It allows us to check the proportions of the...

Cut Grade (5.42)

The research of the cut grade system by GIA included a ray-tracing program and computer modeling programs. Eventually it came down to human observation.

Cut Grade (5.42)

The research of the cut grade system by GIA included a ray-tracing program and computer modeling programs. Eventually it came down to human observation.

Measuring Crown Angles (5.11)

Calculating crown angles of a diamond.

Measuring Crown Angles (5.11)

Calculating crown angles of a diamond.