Mineralogical Characteristic of Hard Substrate Chicken-Blood Stone from Changhua and Its Similar Varieties

To better identify the mineralogical characteristics between the hard substrate chicken-blood stone from Changhua and its similar varieties, samples obtained from the market with real "blood" and fake "substrate" were deeply studied. In this study, hard substrate chicken-blood stone from Changhua and its similar varieties (named as Xi'an, Guizhou, Qinghai and Sichuan "chicken-blood stone") were collected. In order to study the mineralogical differences such as the main mineral components, mineral assemblage characteristics, and chemical compositions between hard substrate chicken-blood stone from Changhua and its similar varieties, polarizing microscope, X-ray powder diffraction (XRD) and electron probe microscope analysis (EPMA) were employed. In the studied samples, there are four different characteristics between hard substrate chicken-blood stone from Changhua and its similar varieties: (1) Mineral assemblage characteristics. Besides cinnabar and quartz, the hard substrate chicken-blood stone from Changhua contains illite, dickite, diaspore and pyrite, while its similar varieties contain metal sulfide, barite and dolomite. The cinnabar in Qinghai "chicken-blood stone" occurs as obvious two-stage mineralization; (2)"Blood" distribution. The cinnabar is massive and occurs as spotted distribution in hard substrate chicken-blood stone from Changhua while its similar varieties present reticular, disseminated, cobweb and granular distribution characteristics; (3)The cell parameters of cinnabar. The cinnabar of hard substrate chicken-blood stone from Changhua and its similar varieties meet the structural characteristics of tripartite system, but the cinnabar in the hard substrate chicken-blood stone from Changhua has parameters of a larger a-axis length and a shorter c-axis length, comparing to the cinnabar in the other samples; (4)Elemental composition of the "blood". There is no Cu in the "blood" of the hard substrate chicken-blood stone from Changhua and no Sb in the cinnabar of the Qinghai and Sichuan "chicken-blood stone". Combined with microscopic features, the Hg in the Guizhou, Qinghai, and Sichuan "chicken-blood stone" are likely replaced by a small amount of Fe, Ni, Cu and other elements. And the cinnabar in Qinghai "chicken-blood stone" occurs as obvious two-stage mineralization.