Grading Proportions-Pavilion & Culet-And Evaluating Finish (Chapter 15, Key Terms & Key Concepts) Flashcards
The care that goes into the fashioning of a polished diamond, as confirmed by its finish
Caftsmanship
The size of the facet at the bottom of
the diamond where the pavilion mains meet
Culet size
A diamond’s physical shape, including its
proportions and durability, determined by decisions
made during the fashioning process.
Design
The quality of the polish and precision of the
cut of a fashioned gemstone
Finish
Girdle thickness
expressed as a percentage of average girdle diameter.
Girdle thickness percentage
The length of the
lower half facets expressed as a percentage of the
total distance between the girdle and the culet.
Lower half length percentage
The angle formed by the pavilion
mains and the girdle plane
Pavilion angle
The distance from the
girdle plane to the culet, expressed as a percentage
of average girdle diameter
Pavilion depth percentage
A diamond’s pavilion makes a significant contribution to its
brightness and fire.
Key Concept
An estimate of a diamond’s pavilion depth percentage is
usually accurate enough for grading and appraising.
Key Concept
Generally, the greater the pavilion depth percentage, the
steeper the pavilion angle.
Key Concept
The purpose of a culet is to prevent abrasion and chipping
on loose diamonds.
Key Concept
The purpose of a culet is to prevent abrasion and chipping
on loose diamonds.
Key Concept
Including design and craftsmanship in the cut grade gives
a well-crafted diamond the recognition it deserves.
Key Concept
Diamonds with thick girdles, steep crowns, or deep pavilions
represent poor value because they appear smaller face-up
than their weights suggest
Key Concept
