Faceting

Cutting & Polishing

Definition

The process of cutting and polishing flat, geometrically arranged faces (facets) onto a gemstone to maximize brilliance, fire, and scintillation in transparent stones.

Detailed Explanation

Faceting began in Europe during the 14th century and transformed the gem trade by dramatically increasing the optical performance of transparent stones. A faceted stone has three zones: the crown (upper portion above the girdle), the girdle (the widest perimeter), and the pavilion (the lower portion below the girdle). The angles and proportions of these zones determine how light travels through the stone. Modern lapidary machines use rotating laps with abrasive surfaces (diamond compound) to grind and polish each facet to precise angles, guided by goniometers.