The objective of this study is to describe the mineralogical composition and chemical properties of the Oraşu Nou bentonite, from northwestern Romania. For mineralogical determinations, the following were used: X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FR-IR), thermogravimetric analysis, scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDX). The chemical compositions and physical properties of the bentonites and bentonitized rocks were also determined. Calcium type montmorillonite is the predominant mineral in this deposit. Its average mass fraction is between 35% and 75%, reaching up to 95%. A small amount of halloysite and very fine cristobalite were also identified in the fine fraction. Quartz, feldspar, and kaolinite were identified as impurities. The average pH of natural bentonite is 6.2. Its cation exchange capacity (CEC) is in the lower-middle range for smectites at 45.89 cmol/kg, absorption capacity 43.58 mL/g, swelling degree 9.41%. Because of the high amounts and purity of montmorillonite, the valuable component mineral, the way is open to an easy refinement of this important resource. This way very high-quality colloidal suspensions can be obtained which can be used in the most modern applications of micro- and nanostructured materials.

Sodalite is a common feldspathoid in alkaline systems, with some varieties exhibiting notable fluorescence due to impurity activators. This study reports the first documented occurrence and characterization of fluorescent sodalite from the classic Ditrău Alkaline Massif, Romania, where its optical properties were previously undescribed. Sodalite-bearing syenite samples from different perimeters of the massif were investigated using macroscopic UV fluorescence, petrographic microscopy, and vibrational spectroscopy (Raman and FT-IR). The sodalite occurs as a late-stage, interstitial and poikilitic mineral, often associated with alteration to cancrinite. Under long-wave UV (365 nm) light, it exhibits spatially variable fluorescence, from absent in parts of the western Prişca perimeter to strong, uniform orange in the eastern Aurora perimeter. Raman and FT-IR spectroscopy confirmed the mineral’s identity and revealed subtle spectral variations, particularly the presence of a minor cancrinite component in some analyses. The vibrant orange fluorescence is consistent with activation by disulfide radical anion ($S_2^{·-}$) activators, formed in the sulfur- and chlorine-rich late-stage fluids characteristic of the massif’s evolution. The geographic variation in fluorescence intensity serves as a potential indicator of the geochemical heterogeneity of these fluids across the massif, linking the strongest fluorescence to the most evolved portions of the igneous complex. This finding opens a new avenue for using fluorescence as a tool for petrogenetic investigation in this classic locality.

Luminescence spectroscopy is an essential, non-destructive technique for mineralogical identification, yet conventional DIY spectrometers face noise, lossy compression, and low sensitivity when capturing weak Stokes-shifted emissions. To address these limitations, we developed a DIY spectrofluorometer that integrates a microscope objective and a transmission diffraction grating. The optical assembly is completed by a back-illuminated monochrome CMOS sensor (Sony IMX678). The camera is read by a local Python bridge through the manufacturer’s native SDK, which streams the uncompressed 12-bit sensor data to a custom web application (SpectraLib) via WebSockets, bypassing video-driver compression and 8-bit browser-canvas quantization. SpectraLib performs real-time ambient background subtraction and spectral smoothing. The detection capability of the instrument was illustrated by recording the weak liquid water Raman scatter band near 414 nm under 365 nm excitation (long-wave UV). The system characterized photoluminescence of six luminescent minerals from four hand specimens under either 365 nm or 255 nm excitation. It detected the Cr³⁺ R-line emission envelope in ruby at 693 nm, alongside the uranyl (${\mathrm{U}\mathrm{O}}_2^{2+}$) vibronic series in hyalite and chalcedony between 504 and 573 nm. It also resolved the broad radiation-induced yellow emission band in zircon centered near 600 nm. Additionally, the system resolved the characteristic orange-yellow emission of sodalite near 625 nm and the deep red emission of orthoclase near 690 nm, corresponding to sulfur-radical and trivalent iron activators, respectively. Emission spectra were visualized using real-time CIE 1931 chromaticity approximations, yielding uncorrected, instrument-dependent color estimates. Crystalline phases were verified via complementary Raman and FT-IR spectroscopies. With a total component cost of approximately $680, this open-architecture spectrofluorometer provides a web-based, high-dynamic-range alternative for educational and laboratory mineralogy, with prospective field applications.