Which term is the result achieved by adding the smallest and largest girdle measurements of a round brilliant and dividing by two?

Which term is the result achieved by adding the smallest and largest girdle measurements of a round brilliant and dividing by two?

• A. Average girdle diameter
• B. Aggregate
• C. Alluvial deposit
• D. Angle of incidence

Answer: (A)

This question tests how to derive the overall diameter measurement used for a round brilliant by averaging the extreme girdle diameters. In a round brilliant, the girdle width is measured in two perpendicular directions: the smallest width (the minor axis) and the largest width (the major axis). When you add these two and divide by two, you get the average girdle diameter, which provides a practical diameter value when the stone isn’t perfectly circular. The term for this mean width is average girdle diameter. The other terms don’t fit here: aggregate and alluvial deposit are geology terms, and angle of incidence is an optics concept related to light, not diamond measurements.

This question tests how to derive the overall diameter measurement used for a round brilliant by averaging the extreme girdle diameters. In a round brilliant, the girdle width is measured in two perpendicular directions: the smallest width (the minor axis) and the largest width (the major axis). When you add these two and divide by two, you get the average girdle diameter, which provides a practical diameter value when the stone isn’t perfectly circular. The term for this mean width is average girdle diameter. The other terms don’t fit here: aggregate and alluvial deposit are geology terms, and angle of incidence is an optics concept related to light, not diamond measurements.