Durability of Fracture-Filled Emeralds with a New Artificial Filler ExCel

• Published in: Key Engineering Materials Vol. 680; pp. 562 - 566
• Main Authors: Chen, Xiao Lei, Lu, Tai Jin, Chen, Hua, He, Ming Yue
• Format: Journal Article
• Language: English
• Published: Zurich Trans Tech Publications Ltd 01.02.2016
• Subjects: Acetone; Bisphenol A; Cracks; Durability; Emerald; Fillers; Heating; Hydrochloric acid; Durability; Excel; Filler; Emerald
• ISBN: 9783038357278; 3038357278
• ISSN: 1013-9826; 1662-9795; 1662-9795
• DOI: 10.4028/www.scientific.net/KEM.680.562

Emerald is the green to greenish blue variety of beryl, which contains chromophore chrome and vanadium. Emeralds of all deposits have fissures, so most have been filled to avoid fragmentation during cutting. Stability is an important factor to filling emeralds. Recently, a new filler ExCel occurred, which is considered stable and removable, however, its durability is lack of scientific basis and testing. This study used magnification, fluorescence technology, FTIR and UV-Vis spectroscopy to investigate the durability of ExCel-filled emeralds. Emeralds filled with ExCel are relatively stable under conditions of daily wear in general, but durability decreased in hydrochloric acid, acetone or under heating to over 200°C. Fractures were more evident in side of emerald after hydrochloric acid immersion. After soaking in acetone fissures increased and deepened significantly. After heating to 250°C, brown material leaked from fissures of ExCel-filled emeralds, analyzed to be bisphenol A epoxy resin, curing agent and imine diluent components. The study has indicative significance for suitable conditions of ExCel-filled emerald wearing and preservation.