Gemology, Mineralogy, and Spectroscopy of an Attractive Tremolitized Diopside Anorthosite Gem Material from the Philippines: A New Type of Material with Similarities to Dushan Jade

In recent years, a new type of material called Philippines “Dushan jade” has appeared in the gemstone market China. This material, very similar appearance and physical properties to Dushan jade, an important ancient jade with long history China, is causing confusion poses identification difficulties. Microscopy, electron probe microanalysis, Fourier transform infrared (FTIR) spectroscopy, Raman microprobe ultraviolet-visible (UV-Vis) spectroscopy were used study gemology, mineralogy, rock samples from order differentiate them jade. The studies showed that composed mainly anorthite minor amounts diopside, tremolite, uvarovite, titanite, chromite, zoisite, prehnite, thomsonite-Ca, chlorite, among which tremolite are main color minerals. origin related electronic transitions involving Cr3+, Fe2+, Fe3+, charge transfer between ions. paragenetic mineral formation sequence can be divided into three stages: (1) magmatic stage: phenocryst, titanite formed first magma; (2) metamorphic phenocryst undergo fracture recrystallization; early fluid intrusion transforms diopside forming uvarovite-grossular-andradite solid-solution around chromite; (3) late hydrothermal solution fills fractures zoisite being formed. From comparison studies, it was established two completely different material. should “tremolitized anorthosite”.