The No. 5 pegmatite vein is the most evolved and well mineralized vein in the Renli deposit, with beryl being the most important beryllium mineral. The vein represents one of the most important gem-quality aquamarine mines at Renli. In this study, beryl crystals from the No. 5 pegmatite vein were examined by EMPA (electron microprobe analysis), ICP-MS (inductively coupled plasma-mass spectrometry), XRD (diffraction of X-rays), FTIR (fourier transform infrared spectrometer), and Raman analyses. Field and petrographic observations showed that most beryl crystals are euhedral to subhedral with light to medium blue color. EMPA analyses indicated that the main chemical compositions of beryl are close to the ideal values, with relatively low Fe (0.222–0.690 wt%) and alkali metal (0.280–0.820 wt%) contents. Geochemical and spectroscopic analyses indicated that cations replacement in beryl is relatively simple. The substituting cations of beryl in the octahedral Al site include mainly: Mg²⁺, Fe²⁺, Fe³⁺, Mn²⁺, Cr³⁺, Ti⁴⁺, and the excess Si. The tetrahedral Be site is mainly replaced by Li. Alkali metals in channel (esp. Na) serve as a charge compensator. According to the Fe-Mg-alkali and Li-Cs contents, the beryls from No. 5 pegmatite belong to the low Li-Cs and low Fe-Mg-medium alkali beryl groups. Field and geochemical data indicated that the No. 5 pegmatite vein formed by the multistage Mufushan granitic pluton emplacement and the magma source was less evolved.

Raman spectra of fluid inclusions in gem rubies from Yuanjiang deposit (China) within the Ailao Shan-Red River (ASRR) metamorphic belt showed the presence of compounds such as CO₂, COS, CH₄, H₂S, and elemental sulfur (S₈), accompanied by two bands at approximately 2499 and 2570 cm⁻¹. These two frequencies could be assigned to the vibrations of disulfane (H₂S₂). This is the second case of the sulfane-bearing fluid inclusions in geological samples reported, followed by the first in quartzite from Bastar Craton of India. The H₂S₂ was likely in situ enclosed by the host rubies rather than a reaction product that formed during the cooling of H₂S and S₈, suggesting sulfanes are stable at elevated temperatures (e.g., >600 °C). By comparing the lithologies and metamorphic conditions of these two sulfane-bearing cases (Bastar and Yuanjiang), it is suggested that amphibolite facies metamorphism of sedimentary sequence that deposited in a continental platform setting might favor the generation of sulfanes. Sulfanes may play an important role in the mobilization of Cr that is essential for ruby crystallization.

The Dongxiang tungsten–copper deposit is a large W–Cu deposit located in the northeast of Jiangxi province in south China. Previous studies have mainly considered the geochemical and isotopic attributes of the ore deposit, but information is still lacking on the genesis and setting of Dongxiang W–Cu mineralization-related intrusive rocks. This paper presents systematic elements and Sr–Nd–Hf isotopic data of the Dongxiang granodiorite porphyry. The Dongxiang granodiorite porphyry is intermediate–acidic in composition, with SiO₂ contents of 60.00–75.16 wt.%, Al₂O₃ contents of 10.15–18.53 wt.%, an K₂O contents of 2.95–4.28 wt.%. The REEs content ranges from 64.2 to 198.1 ppm, with LREE/HREE ratios of 7.67–17.47. It is characterized by adakitic geochemical affinities with high Sr/Y and (La/Yb)_N ratios but low Y and Yb contents. A slight Eu anomaly, extreme depletion in Y and Yb, relatively low MgO content, and relatively high ²⁰⁷Pb/²⁰⁴Pb ratios together indicate that the Dongxiang granodiorite porphyry was likely derived from partial melting of the thickened lower continental crust. Based on zircon ε_Hf(t) values (−11.8–−4.5), two-stage Hf model ages (1.33–1.94 Ga), and the regional geological setting, it can be inferred that Dongxiang granodiorite porphyry magma is mainly derived from Neoproterozoic juvenile crust with the involvement of Paleoproterozoic ancient crust.

Most of the diamond deposits in China are in the North China Craton. In addition to gem diamonds in kimberlite, a large number of microdiamonds have also been discovered in alkaline dolerites. These microdiamonds show very different characteristics from those recovered in kimberlite. Here, we report the morphology, colour, nitrogen contents, and carbon isotopic compositions of the diamonds recovered from the alkalic dolerites in eastern China. The microdiamonds are mainly cube and rhombic dodecahedron with diameters of 0.2 to 0.6 mm. Infrared spectrum analysis shows that these microdiamonds are mostly type Ib with a small amount of type Ia. The Y centre is obvious in type Ib diamond. Modelling mantle residence times for the IaAB diamonds is about 550 Ma. Nitrogen contents of the diamonds range from 4.5–503 ppm, with a median value of 173 ppm. The total δ¹³C range of the microdiamonds varies between −18.6 and −21.1‰ and are similar to those of ophiolite diamond.