Minimum nacre thickness 0.8mm and up.
Luster is good to soft, with fair rate of reflection.
Detailed facial features are typically not observed on pearl surfaces.
Reflected light sources have blurred, satiny edges.
Blemish rate less than 30% on each pearl surface.
One to two heavy blemishes allowable on 18-inch strand.
Very good matching; little variation in color, tone, luster, shape or size