When a piece of nephrite jade is naturally tumbled in a river over thousands of years, it is randomly struck by other pebbles of various sizes, shapes and hardnesses. The result is a pattern of impact pits (termed ‘sweat pores’ by Chinese gemologists) that vary in depth, size and shape. Examining the impact pits on the surfaces of nephrite pebbles provides important clues in separating natural river jade from mountain jade that has been artificially tumble to mimic it.
Natural • Nephrite • Jade • China; Hetian, Xinjiang • Enhancements: None Detected (None) • Lighting Conditions: Fiber Optic: Diffuse Overhead
Photographer: Richard W. Hughes •
Image Number: A-003-9207-1 • Field of View = 8 mm • Date Posted: 02 July 2021
Hughes, R.W., ed. (2022) Jade • A Gemologist’s Guide. Bangkok: RWH/Lotus Publishing.