... Formation, southern Negev Desert, Dead Sea basin, Israel. The mineral occurs in sulfide-calcite assemblages confined to black-colored calcite-spurrite marbles. It forms single-crystal grains up to 1 mm in size, isometric to lath-like, and often intergrown with a less-common rasvumite, KFe 2 S 3 . Associated...

... across. (Color online.) Figure 2. Crystal drawing of cabrerite, clinographic projection. Cabrerite is optically biaxial (+) with α = 1.609(2), β = 1.633(2), γ = 1.667(2) measured in white light. The 2 V measured directly on a spindle stage is 82(2)°; the calculated 2 V is 81.6°. Slight...

...Chengsi Wang; Andy H. Shen; Peter J. Heaney; Aaron Palke; Ke Wang; Haiying Wang; Lore Kiefert Abstract The coloration mechanism of Oregon sunstone is a classic and controversial topic in mineralogy because of the unique coexistence of anisotropic (green-red) and isotropic (red) color zones within...

...Matthew J. Kohn Abstract Mineral separates mounted in thin section help introduce mineralogy students to concepts of relief, color, pleochroism, and birefringence and serve as reference materials both for research and teaching. Here, a simple method is described to produce materials that can...

... regional trough, special attention was paid to the dark-colored lithotypes during the research. It was revealed that among the studied samples, the dark color of some of them was of mineral nature, rather than due to the presence of OM. In these samples, the mineral composition was studied in detail...

... are investigated in this work based on oil geochemistry, fluid inclusion analyses, and in situ U-Pb dating of calcite cements. Four charge episodes are identified based on the following: (1) the similar origin but different maturation histories of sampled crude oils; (2) the four distinct fluorescence-color...

... with albite, calcite, and mimetite. It is a secondary oxidation-zone mineral presumably crystallized from hydrothermal solutions. Gysinite-(Ce) occurs in intergrowths of equant pseudo-octahedral crystals, up to about 0.7 mm in maximum dimension. The color is brownish yellow, the streak is pale yellow...

... collapsing gully. By comparing the soil weathering degree (in terms of the colour, soil texture and soil structural characteristics), the granite soil layer of the study area can be subdivided into three parts: red soil layer, sandy soil layer and detritus layer at the bottom ( Luk et al. 1997 ). Therefore...

...Yue Yin; Fabio Crameri; Grace E. Shephard; Philip J. Heron A number of widely used colour palettes applied to display critical scientific results not only distort data but are also inaccessible to a proportion of the population. An issue with the rainbow palette (and variants such as “jet...

... from a Li-rich pocket. (Color online.) Apatite samples were taken from all the zones of the pegmatite. Those from the core zone, where apatite is especially abundant in some of the pockets and in some elongated “seams,” are the best-represented samples. Characterization of apatite was carried...

.... However, no one has confirmed the color of the nectar and prior to our study, no one had conducted a palynological analysis of the purple honey to test this hypothesis. A second hypothesis is that the unusual color comes from bees rasping or scavenging sweet juices from ripening berries. Berries injured...

... of formation in an exceptionally Ni-rich environment. The high abundance of exsolved rutile inclusions imparts a dominantly brownish-gray color to the corundum, which precludes it from being of gem quality. Chromium-bearing corundum has been suggested as a possible indicator mineral for metamorphosed massive...

..., but it is estimated to be 200 m long and 45 m wide ( Gordon & Masson 1980 , Ercit 1994 ). It is well-zoned, with three recognizable units: (1) a wall zone containing microcline, albite, and quartz, (2) an intermediate zone of microcline and quartz, and (3) a quartz core, which ranges in color from colorless...

... and facetted Paraíba tourmaline displaying the desired brilliant neon blue color. Crystal weighs 8.80 ct, from Brazil. The facetted stone is a 10.91 ct neon blue Paraíba tourmaline (no heat) from the Batalha mine, Brazil. Cut gem courtesy of a Private Collector and Mona Lee Nesseth, Custom Estate Jewels. Photo...

... in the different colour intensity areas/bands of aquaprase and agate, whereas chrysoprase exhibited a more homogeneous coexistence of micro- and cryptocrystalline quartz. High-resolution synchrotron XRD was essential for highlighting the complex assemblage of various types of α-quartz in aquaprase and agate (which...

... report the geological data with colour and the description of the units, organised according to their age, is provided by a coloured legend. Since geological maps are a mixing between observable and interpreted data of a science, geology, that is still evolving, they should be subjected...

... of specific luminescence emission bands to different defect centers causes a diversity of CL characteristics and visible CL colors in dependence on the processes of mineral formation or alteration ( Ramseyer et al. 1988 ; Götze et al. 2001 , 2021 ). Therefore, the knowledge about the origin of different...

...Michail N. Taran; Oleksii A. Vyshnevskyi; Charles A. Geiger Abstract Synthetic flux-grown end-member gahnite, ZnAl 2 O 4 , and several different colored crystals doped with one or more transition metals including Mn, Ni, Cr, Co, and Fe were studied by electron microprobe methods and UV/Vis/NIR...

...Cong Tan; Bingsong Yu; Ce Liu; Zhenglin Cao; He Bi; Hui Jin; Rongjun Yang Abstract The Permian-Triassic strata in the Ordos Basin deposit a colorful set of strata. Although there have been many studies on oil and gas resources here, little attention has been paid to the genesis mechanism of its...

... province in southern Libya and then characterised by applying a combination of the SEM–WDS, ICP/OES, PXRD and IR methods. Colour variations and related minerogenetic frameworks were also investigated. Three samples have greenish-blue-to-blue colour (480.4–482.5 nm), whereas the other two samples have blue...