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Gadolinite [REE2Fe2+Be2Si2O10] is a common mineral in certain types of rare element and rare earth element (REL-REE) pegmatites. Changes in pegmatite environment during and after gadolinite formation may be devised by studying its crystal-chemical properties and a thorough observation of microfeatures in the mineral matrix. Post-crystallization processes in pegmatite might trigger alteration mechanisms in gadolinite like in other REE-rich pegmatite minerals, whereby various late-magmatic or metasomatic events may affect mineral chemistry. Three gadolinite samples originating from various pegmatite occurrences in southern Norway offer an excellent opportunity in studying post-crystallization evolution of the pegmatites; by determining their crystallographic, chemical, and micro-textural features, imprints of the related processes in the pegmatites have been characterized in this study. Relevant mineral information was collected in recrystallization experiments of fully or slightly metamictized gadolinite samples and subsequent XRD analyses. Micro-Raman spectroscopy, electron microprobe analysis (EMPA), and scanning electron microscope–backscattered electron–energy-dispersive X-ray spectroscopy (SEM-BSE-EDS) analyses were employed to retrieve micro-chemical properties and related micro-textural features of the mineral matrix. With a reference to the gadolinite supergroup, a general alteration path can be envisaged outlining the pegmatite evolution and suggesting the occurrence of the secondary REE mineral phases: altered gadolinite domains prove Ca enrichment with a tendency toward the hingganite composition, while a slight fluorine increase and sporadic secondary fluorite occurrence imply a significant role of fluorine as a complexing agent in the dissolution-reprecipitation mechanism of metasomatic alteration in the mineral. Micro-Raman spectra show improved vibration statistics for the altered gadolinite domains, which could be linked to the substitution of rare earth elements (REE) by Ca and a possible increase of structural ordering within the gadolinite structure, being at the same time an indication of structural healing of metamictized domains by metasomatic processes. A study of microfeatures in the complex silicates like gadolinite proves to be an excellent tool to trace post-crystallization processes in a pegmatitic environment. With a slight redistribution of radionuclides during an alteration in gadolinite, a moderate precaution has to be taken when selecting gadolinite for U-Th-Pb dating.

Middle and Upper Pleistocene loess-palaeosol sequences up to 90 m thick are exposed on the Island of Susak located in the Northern Adriatic Sea in Croatia. During glacial times the sea level was up to about 120 m lower and a significant part of the Adriatic became land. The source area of the primary aeolian sediments was in the vicinity of the island and is related to the southward extended River Po plain. The loess has a mainly clayey to sandy silt or sand grain-size and is intercalated by at least three tephras, numerous palaeosols and calcareous segregations. The heavy mineral association points to metamorphic and igneous rocks from Alpine regions as source material of the loess. Geochemical and mineralogical properties of loess and palaeosols differentiate one from another and reflect the intensity of weathering and pedogenesis. The oldest tephra contains vitroclasts and serrated clinopyroxene while the middle and the youngest tephra along with vitroclasts, contain idiomorphic augite as diagnostic volcanic features. Based on bulk rock and vitroclast chemistry, morphology of pyroxenes, and the age of the loess sandwiching the tephra, the potential source of this volcanic material could very likely be the Campanian or Aeolian volcanic province in southern Italy. Infrared stimulated luminescence dating-results show that the major part of the aeolian deposits including the tephra layers correlates to MIS 3-MIS 5.

In this study we present morphological, molecular and ecological features of the last instar larvae of Drusus bosnicus with data about distribution of this species in Bosnia and Herzegovina. We also included are the most important diagnostic features enabling separation of larvae of D. bosnicus from larvae of the other European Drusinae and Trichoptera species.

Ispiranje zlata iz recentnih i starih nanosa rijeka i potoka, jedan je od najstarijih oblika rudarenja, koji seže u predmetalno doba razvoja civilizacije (bakar i željezo). Razlog treba tražiti u neposrednoj upotrebi zlata bez znanja složene tehnologije pridobivanja čistog metala. Separacija teških minerala u vodotocima odvija se jednostavnim prirodnim procesom odnošenjem lakših mineralnih frakcija vodenom strujom. Postupci ispiranja zlata, korišteni od čovjeka, nisu ništa drugo nego kopiranje prirodnog procesa, uz male domišljate varijacije priručnog alata. U radu je opisana kratka povijest zlatarstva na Dravi, te data temeljita analiza geološke geneze zlatnih nanosa i mineraloški sastav dravskog zlata., Gold panning from recent and old river and stream deposits is one of the oldest forms of mining, dating back to the pre-metal ages of the development of civilisation (Copper and Iron Ages). The reasons should be sought in the direct use of gold without the knowledge of the more complex technologies of obtaining pure metal. The separation of heavy minerals in watercourses is carried out by the simple natural process of separation of lighter mineral fractions by the water current. The procedure of gold panning as used by man is none other than copying this natural process, with a few interesting variations using the available tools. This paper provides a short history of gold panning on the Drava River, and a comprehensive analysis on the geological genesis of gold deposits and the mineralogical composition of the Drava River gold.

In this study we present morphological, molecular and ecological features of the last instar larvae of Drusus bosnicus with data about distribution of this species in Bosnia and Herzegovina. We also included the most important diagnostic features enabling separation of larvae of D. bosnicus from larvae of the other European Drusinae and Trichoptera species.

Modified hydrothermal and ‘wet’ precipitation routes at room temperature were employed to synthesise pure monoclinic BiVO 4 powders of varying particle morphologies. Monoclinic BiVO 4 powder was also prepared by a solid-state reaction at 700°C. Depending on the synthesis conditions, the colour of BiVO 4 varies from inhomogeneously yellow–brown to homogeneously and intensive lemon yellow. BiVO 4 prepared by solid-state reaction consisted of large compact particles about 15 μm in size and of irregular shape. At higher magnification, the formation of domains with smooth terrace-like surfaces was observed. These domains ended with well-defined walls, and the edges of these walls were relatively very sharp. BiVO 4 synthesised by the hydrothermal and an aqueous process at RT consisted of smaller particles (0.3–1.2 μm) and of much bigger regular crystals with a well-defined crystal habit. A continuous shift of the most intense Raman band to lower wavenumbers reveals that the average short range symmetry of the VO 4 tetrahedra becomes more regular. The values of FWHM for the same Raman band increase from sample prepared by solid-state reaction to sample obtained at RT. The Raman results suggested that a sample prepared at high temperature consisted of less symmetric VO 4 tetrahedra than samples prepared at low temperature and that the high-temperature sample showed better crystallinity with less defects than the samples prepared by an aqueous process under mild conditions. FT-IR spectra showed main features typical of the vanadates of other metal(3+) cations. However, the position of IR bands recorded for BiVO 4 depended on the synthesis route.