Dyed Green Marble Imitating Jadeite
Although marble is fairly abundant, calcite’s low hardness and easily visible cleavages do not make it a viable substitute for jadeite. Yet it does lend itself well to carving. Chinese merchants often sell untreated carved marble by the trade names “Hanbai jade” or “Afghanistan jade,” or even offer such material as “antique jade.” Jade, pronounced “yu” in Chinese, is a general term that typically applies to aggregates of minerals. Marble in the Chinese jewelry market is frequently fashioned into bangles and carved pendants, and some may subsequently be dyed or partially dyed to imitate jadeite jade. Although it was impossible to calculate the SG of this mounted specimen, calcite’s RI of 1.65 overlaps with jadeite jade’s, leading to the possible misidentification of such material (J.M. Hobbs, “The jade enigma,” Spring 1982 G&G, pp. 3–19).
Figure 2. Raman peaks at around 1084, 712, 275, and 145 cm–1 were consistent with calcite.
The identification was determined using Raman and FTIR spectroscopy. The sample showed Raman peaks at around 1084, 712, 275, and 145 cm–1 (figure 2), with IR peaks at around 1445 and 878 cm–1. Microscopic observation revealed a network of dyed grain boundaries (figure 3). The dye treatment was confirmed with the spectroscope, where a single broad band typical of some green dyes was clearly evident in the red-orange region. Long-wave UV did not offer any distinction. Although destructive tests are always avoided, the client allowed us to gently scratch the surface with a metal pointer, which confirmed the material’s low hardness. This submission reinforces the need to consider all types of material when dealing with items resembling jadeite. 
Figure 3. Microscopic observation revealed a network of dyed grain boundaries. Photo by Lai Tai-An Gem Lab; magnified 50×.
