Gemmological and Mineralogical Characteristic of Quartz Jade from Jingshan

The quartz jade from Jingshan is named from a mountain from Baokang country, Hubei Province, which is a new type of quartz jade and characterized by bright colours, high degree of hardness, unique breccia texture and easily caved.Without large-scale advertising, the popularity and market recognition of the quartz jade from Jingshan are far less than those of Huanglong jade and nanhong agate.According to the old documents, the quartz jade from Jingshan, "Jing jade" and He's jade represent the local culture of the Jingchu area, central China.The quartz jade from Jingshan is of extremely high research and collection values.
Methods, including polarizing microscope, X-ray powder diffraction, chemical analysis and infrared spectroscopy were used to study the chemical composition, and mineral component of the quartz jade from Jingshan.The results showed that the quartz jade from Jingshan is dominant by quartz with trace hematite, goethite, apatite, calcite, dolomite and sericite.SiO₂ is the major chemical composition, with Na₂O, MgO, Al₂O₃, P₂O₅, K₂O, CaO, Fe₂O₃ and FeO.TFe/Ti and Al-Fe-Mn diagram suggest that the quartz jade from Jingshan was precipitated by hydrothermal sedimentary genesis.The quartz jade from Jingshan samples is mainly brecciaous or massive with yellow or red colours, and of being cryptocrystalline, cryptocrystalline-microcrystalline structure, mosaic or brecciaous texture under the optical microscopy.Fe element exists in iron oxides and hydroxides such as goethite, lepidocrocite and hematite, and its valence and content affect the hue and concentration of quartz jade from Jingshan.