Mineralogical and Spectroscopic Characteristics of Hard Substrate Chicken-Blood Stone from Changhua and Its Similar Jade

With the mineral resource decline of chicken-blood stone, a wide variety of similar jades have appeared on the market. The main mineral compositions of these similar jades are mostly quartz, which is easily confused with the traditional hard substrate chicken-blood stone from Changhua. To identify and name these varieties of similar jades, this study chooses several similar jade samples from Sichuan, Guizhou, Xi'an and Yunnan and compared them with hard substrate chicken-blood stone samples from Changhua to analyze their differences in mineralogical and spectroscopic characteristics. X-ray powder diffraction spectrometer, infrared spectroscopy, laser Raman spectroscopy and scanning electron microscopy are used in this study. The results are as follows: (1) XRD results show that the hard substrate chicken-blood stone samples are composed of quartz and dickite. The main constituent minerals of the similar jade samples are quartz and carbonate minerals. (2) According to absorption peaks of IR, the hard substrate chicken-blood stone and its similar jade can be identified and differentiated quickly. Carbonate absorption peaks of 1 450, 881 cm^-1 and 729 cm^-1 often appear in infrared spectra of similar jade samples, while the hard substrate chicken-blood stone samples from Changhua show characteristic absorption peaks of quartz. (3) Raman spectra results show that all samples have quartz characteristic Raman shift, but the similar jade samples from Sichuan, Guizhou and Yunnan also have calcite Raman shift. Similar samples from Xi'an have dolomite Raman shift. The matrix part of hard substrate chicken-blood stone from Changhua often contains anatase, which can not be found in the similar jade samples. For the yellow minerals around cinnabar, in hard substrate chicken-blood stone sample from Changhua, it is pyrite with Raman shift at 340,374,426 cm^-1, but in the similar sample from Guizhou, it is realgar. (4)SEM results show that the differences in the micro-morphological characteristics of hard substrate chicken-blood stone and its similar jades primarily resided within carbonate minerals. The carbonate minerals in similar jades are flakes stacked in imbricate stacking. The cleavage surface and step-like fracture of carbonate minerals are commonly observed in similar jades, while the hard substrate chicken-blood stone has no such phenomenon. According to the test results and the national standard, these kinds of similar jade samples should be named as cinnabar bearing carbonate-quartz jade.