Ruby and sapphire rough from Muling exhibited well-formed tabular hexagonal crystal forms some sapphires showed a tumbled appearance in broken pieces. Other varieties of sapphire had no reaction under long- or short-wave UV.įigure 2. Rubies and pink sapphires exhibited medium red fluorescence under long-wave (356 nm) UV light and a weak reaction under short-wave (245 nm) UV. Samples other than the deep blue material showed high transparency. Most of the rubies and pink sapphires had a purplish component. The sapphires were pink, yellow, violetish blue, greenish blue, light blue, and deep blue there were also near-colorless specimens. Most exhibited well-formed tabular hexagonal crystals, though some broken sapphires had a tumbled appearance.

The stones ranged from 0.8 to 15.2 ct (figure 2). We acquired a parcel of rubies and sapphires from local miners. As colored stones became more popular in the Chinese gem markets, interest in ruby and sapphire from Muling grew accordingly.

Chen et al., “ Brownish red zircon from Muling, China,” Spring 2011 G&G, pp. 126–132).Īccording to Aijun Yi, director of mineral resource administration in Muling, the region has produced large amounts of gem-quality eluvial materials since 1994, including corundum, brownish red zircon, garnet, and spinel (T. Sun, “Basalt related to ruby and sapphire in eastern Heilongjiang and reconstruction of paleovolcanic mechanism,” Acta Petrologica et Mineralogica, Vol. As a result, production has been very limited, and very little information was published about rubies and sapphires from Muling until 1995 (J.X. Corundum was known in Muling as early as 1985 after preliminary exploration, further activity virtually stopped because of technical and logistical limitations. The main deposits are seated in mountain valleys about 70 km from the town center. An emerging deposit in Muling, in northeast Heilongjiang province (figure 1), produces gem-quality corundum comparable to some world-renowned sources. Only a few Chinese sources produce gem-quality corundum, such as Changle, in Shandong province, but sapphires from that location are not considered top quality in the trade because of their dark hues. Muling, the site of an emerging corundum deposit, is located in northeastern China. Comprehensive CAD/CAM For Jewelry Certificateįigure 1.

Ruby sapphire gem