Greenish Yellow Research Articles

Cholesterol–based Bisamides on Biphenyl Backbone: A Case of Selective Visual Sensing of F− and H2PO4− through Breaking and Making of Gels

AbstractCholesterol linked bisamides 1–3 on biphenyl spacers have been designed and synthesized. Compound 1 forms gel in CHCl3 – n‐hexane (1:6, v/v) solvent and the gel is selectively collapsed into sol in presence of F− with a color change from yellowish white to greenish yellow. Presence of pyridinium amides in 2 and 3 showed different gelation behaviours. While the chloride salt 2 displayed gelation in CHCl3 in presence of H2PO4−, compound 3 formed gel in DMSO: H2O (1:2, v/v) without having any assistance of externally added anion. The gel derived from 3 underwent rapid gel to sol transition in presence of H2PO4− and F− anions and validated their visual sensing.

52-3:Distinguished Paper: 3 Stacked Top Emitting White OLED for High Resolution OLED TV

In this work, we report top emission white OLED (TE-WOLED) device for an application to large sized and high resolution OLED TV. Like as bottom emission device, we adopted 3 stack WOLED consisting of two blue and one yellow green (YG) light-emitting units with a reflective metal as the bottom anode and a transparent compound as the top cathode. By using an optical simulation, we designed the device structure and found optimum positions for EML with consideration of viewing angle property. As a result, we demonstrate top emission white OLED comparable to bottom emission OLED, regarding efficiency, operating voltage and viewing angle.

45-1:Invited Paper: Recent Progress of White Light-Emitting Diodes for an Application to New Models of OLED TV

This paper will explain recent progress of WOLED for OLED TV which has been made by introducing an additional blue unit to conventional 2- stack tandem WOLED consisting of blue and yellow green (YG) devices. The addition of the blue unit not only boosts blue subpixel efficiency, but also makes the correlated color temperature of WOLED increase, resulting in more energy-efficient OLED TV. How the detailed architecture in the 3-stack WOLED is determined will be described, in consideration of color shift dependent on a viewing angle.

Photophysical Properties of Synthetic Food Dyes

The photophysical properties of generally-recognized-as-safe (GRAS) food dyes, such as Allura Red (AR), Tartrazine (TR), Sunset Yellow (SY) and Fast Green (FG), have rarely been reported. All these dyes exhibit very weak emission in common fluid solvents, which can explain the limited information on their photophysical properties. A significant enhancement of fluorescence emission is observed in highly viscous solvents (glycerol, etc.) and structured systems (e.g., amorphous solids, fat crystal networks, etc.). This observation has supported the hypothesis that these dyes exhibit molecular rotor behavior enabling their use as probes of microviscosity. To enhance the applicability of these potential luminescent probes, detailed information on their photophysical properties was gathered in this study. Their excitation and emission spectra were collected and Stokes shifts analyzed in a series of solvents of different polarity. Additionally, fluorescence quantum yields and lifetimes of all the dyes were determined in water:glycerol mixtures (0-98% glycerol). TR exhibited the largest Stokes shift (Δν = 5000 cm-1), followed by AR and SY (Δν = 2500 cm-1) and finally FG (Δν = 700 cm-1). The effect of environmental polarity on the fluorescence emission peak location was more pronounced for AR than for the rest of the probes. For dyes in water at 296K, the fluorescence quantum yields (Q) and lifetimes (τ) were extremely small (0.0001-0.0005 and 10-20 ps, respectively). However, for all dyes, a significant increase in Q and τ was observed by increasing medium viscosity at fixed temperature (increasing glycerol content in water:glycerol mixtures), by reducing the temperature to 77K, or by a combination of both, reaching values as high as Q = 0.41 and τ = 3.37 ns for FG in glycerol at 77K.This study makes a significant contribution to the currently incomplete photophysical characterization of these edible and safe-to-ingest fluorophores.

Studies on dyeing and value-addition of ornamental grassLagurus ovatus

Lagurus ovatus (hare tail grass) is a winter season grass which is utilized in dry flower industry in preparation of various types of value-added products like flower arrangements, hangers, wall pictures etc. Different dyes like Fabric dyes, indicator dyes, food dyes and bio-colours were used for colouring this grass. Findings revealed that among four different categories of dyes fabric dyes i.e. Yellow, Dark green, Violet, Magenta Pink and indicator dyes Brilliant Green, Eosin Yellow and Crystal Violet were the excellent in performance for dyeing of Lagurus ovatus in terms of colour intensity and colour absorption. These dyes scored maximum for quality parameters even after ten months of storage. Quality parameters in case of food dyes were medium to high at the time of dyeing but the colours faded very fast and retention was not good after ten months. Out of the bio-colours; dyeing with turmeric and lilium pollen were quite satisfactory, whereas other colours like henna powder, gulmehndi (wild henna), coffee, butea, punica, beet root were very poor in performance.

Ethylene glycol mediated synthesis of Ag8SnS6 nanoparticles and their exploitation in the degradation of eosin yellow and brilliant green

Spherical Ag8SnS6 nanoparticles degrades eosin yellow within 45 min under solar irradiation and brilliant green within 90 min under tungsten lamp irradiation. Superoxide anions are the main active species involved in photodegradation of eosin yellow and brilliant green dyes.

黄绿绿僵菌对桃蚜2种酶活性的影响

研究了黄绿绿僵菌对桃蚜GSTs和AChE 2种酶系的影响，结果表明：24 h以后，桃蚜体内AChE的活力急骤下降，直到40 h时达到最低，抑制率为52.81%，其后一直维持在该水平；桃蚜体内GSTs的活力在染菌40 h后，其活力快速下降，直到56 h降到最低，抑制率为38.91%，并保持在该水平。 We study the effect of green to yellow green of Metarhizium anisopliae on Myzus persicae GST and AChE in the two enzymes. The results showed that after 24 h, Myzus persicae in AChE activity dropped sharply until 40 h reached the lowest inhibition rate for 52.81%, followed has been main- tained at the level; Myzus persicae GSTs activity after infected with bacteria and 40 h, the activity decreased rapidly until 56 h reduced to a minimum. The inhibition rate was 38.91% and remained at the level.

Time-Resolved Infrared Reflectance Studies of the Dehydration-Induced Transformation of Uranyl Nitrate Hexahydrate to the Trihydrate Form.

Uranyl nitrate is a key species in the nuclear fuel cycle. However, this species is known to exist in different states of hydration, including the hexahydrate ([UO2(NO3)2(H2O)6] often called UNH), the trihydrate [UO2(NO3)2(H2O)3 or UNT], and in very dry environments the dihydrate form [UO2(NO3)2(H2O)2]. Their relative stabilities depend on both water vapor pressure and temperature. In the 1950s and 1960s, the different phases were studied by infrared transmission spectroscopy but were limited both by instrumental resolution and by the ability to prepare the samples for transmission. We have revisited this problem using time-resolved reflectance spectroscopy, which requires no sample preparation and allows dynamic analysis while the sample is exposed to a flow of N2 gas. Samples of known hydration state were prepared and confirmed via X-ray diffraction patterns of known species. In reflectance mode the hexahydrate UO2(NO3)2(H2O)6 has a distinct uranyl asymmetric stretch band at 949.0 cm(-1) that shifts to shorter wavelengths and broadens as the sample desiccates and recrystallizes to the trihydrate, first as a shoulder growing in on the blue edge but ultimately results in a doublet band with reflectance peaks at 966 and 957 cm(-1). The data are consistent with transformation from UNH to UNT as UNT has two inequivalent UO2(2+) sites. The dehydration of UO2(NO3)2(H2O)6 to UO2(NO3)2(H2O)3 is both a structural and morphological change that has the lustrous lime green UO2(NO3)2(H2O)6 crystals changing to the matte greenish yellow of the trihydrate solid. The phase transformation and crystal structures were confirmed by density functional theory calculations and optical microscopy methods, both of which showed a transformation with two distinct sites for the uranyl cation in the trihydrate, with only one in the hexahydrate.

Adsorption and Corrosion Inhibition Studies of Some Selected Dyes as Corrosion Inhibitors for Mild Steel in Acidic Medium: Gravimetric, Electrochemical, Quantum Chemical Studies and Synergistic Effect with Iodide Ions.

The corrosion inhibition properties of some organic dyes, namely Sunset Yellow (SS), Amaranth (AM), Allura Red (AR), Tartrazine (TZ) and Fast Green (FG), for mild steel corrosion in 0.5 M HCl solution, were investigated using gravimetric, potentiodynamic polarization techniques and quantum chemical calculations. The results showed that the studied dyes are good corrosion inhibitors with enhanced inhibition efficiencies. The inhibition efficiency of all the studied dyes increases with increase in concentration, and decreases with increase in temperature. The results showed that the inhibition efficiency of the dyes increases in the presence of KI due to synergistic interactions of the dye molecules with iodide (I−) ions. Potentiodynamic polarization results revealed that the studied dyes are mixed-type inhibitors both in the absence and presence of KI. The adsorption of the studied dyes on mild steel surface, with and without KI, obeys the Langmuir adsorption isotherm and involves physical adsorption mechanism. Quantum chemical calculations revealed that the most likely sites in the dye molecules for interactions with mild steel are the S, O, and N heteroatoms.

Over-expression of the Hybrid Aspen Homeobox <i>PttKN1</i> Gene in Red Leaf Beet Induced Altered Coloration of Leaves

PttKN1 (Populus tremula × tremuloides KNOTTED1) gene belongs to the KNOXI gene family. It plays an important role in plant development, typically in meristem initiation, maintenance and organogenesis, and potentially in plant coloration. To investigate the gene functions further, it was introduced into red leaf beet by the floral dip method mediated via Agrobacterium tumefaciens. The transformants demonstrated typical phenotypes as with other PttKN1 transformants. These alterations were very different from the morphology of the wild type. Among them, morphological modification of changed color throughout the entire plant from claret of wild type to yellowish green was the highlight in those transgenic PttKN1-beet plants. The result of spraying selection showed that the PttKN1-beet plants had kanamycin resistance. PCR assay of the 35S-Promoter, NPTII and PttKN1 gene, PCR-Southern analysis of the NPTII and PttKN1 gene showed that the foreign PttKN1 gene had successfully integrated into the genome of beet plant. Furthermore, the results of RT-PCR analysis showed that the gene was ectopic expressed in transgenic plants. These data suggested that there is a correlation between the ectopic expression of PttKN1 gene and morphological alterations of beet plants. Pigment content assay showed that betaxanthins concentrations shared little difference between wild type and transgenic lines, while betacyanins content in transgenic plants was sharply decreased, indicating that the altered plant coloration of the transgenic beet plants may be caused by the changed betacyanins content. The tyrosinase study suggested that the sharply decreased of betacyanins content in transgenic plants was caused via the decreased tyrosinase level. Therefore, the reason for the altered plant coloration may be due to partial inhibition of betacyanin biosynthesis that was induced via the pleiotropic roles of PttKN1 gene.

Over-expression of the Hybrid Aspen Homeobox <i>PttKN1</i> Gene in Red Leaf Beet Induced Altered Coloration of Leaves

PttKN1 (Populus tremula × tremuloides KNOTTED1) gene belongs to the KNOXI gene family. It plays an important role in plant development, typically in meristem initiation, maintenance and organogenesis, and potentially in plant coloration. To investigate the gene functions further, it was introduced into red leaf beet by the floral dip method mediated via Agrobacterium tumefaciens. The transformants demonstrated typical phenotypes as with other PttKN1 transformants. These alterations were very different from the morphology of the wild type. Among them, morphological modification of changed color throughout the entire plant from claret of wild type to yellowish green was the highlight in those transgenic PttKN1-beet plants. The result of spraying selection showed that the PttKN1-beet plants had kanamycin resistance. PCR assay of the 35S-Promoter, NPTII and PttKN1 gene, PCR-Southern analysis of the NPTII and PttKN1 gene showed that the foreign PttKN1 gene had successfully integrated into the genome of beet plant. Furthermore, the results of RT-PCR analysis showed that the gene was ectopic expressed in transgenic plants. These data suggested that there is a correlation between the ectopic expression of PttKN1 gene and morphological alterations of beet plants. Pigment content assay showed that betaxanthins concentrations shared little difference between wild type and transgenic lines, while betacyanins content in transgenic plants was sharply decreased, indicating that the altered plant coloration of the transgenic beet plants may be caused by the changed betacyanins content. The tyrosinase study suggested that the sharply decreased of betacyanins content in transgenic plants was caused via the decreased tyrosinase level. Therefore, the reason for the altered plant coloration may be due to partial inhibition of betacyanin biosynthesis that was induced via the pleiotropic roles of PttKN1 gene.

Graphene/BaCrO<sub>4</sub> Nanocomposites Catalyzed Photodegradation and Kinetics Study of Organic Dyes

The <TEX>$BaCrO_4$</TEX> nanoparticles were synthesized from a 0.1 M <TEX>$K_2CrO_4$</TEX> and 0.1 M <TEX>$BaCO_3$</TEX> solution with stirring for 10 h. The product was washed several times with acetone and heated to <TEX>$700^{\circ}C$</TEX> for 6 h. At that time, the color of mixture was a greenish yellow. The graphene/<TEX>$BaCrO_4$</TEX> nanocomposites were prepared with graphene and <TEX>$BaCrO_4$</TEX> nanoparticles by stirring in tetrahydrofuran and heated in an electric furnace at <TEX>$700^{\circ}C$</TEX> for 2 h. The <TEX>$BaCrO_4$</TEX> nanoparticles, graphene/<TEX>$BaCrO_4$</TEX> and heated graphene/<TEX>$BaCrO_4$</TEX> nanocomposites were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The graphene/<TEX>$BaCrO_4$</TEX> nanocomposites and heated graphene/<TEX>$BaCrO_4$</TEX> nanocomposites were evaluated as a photocatalyst and discussed about kinetics study for the degradation of organic dyes, such as methylene blue and rhodamine B under ultraviolet light irradiation at 254 nm.

Studies on vase life of tinted spikes of gladiolus cultivar white prosperity

An investigation was undertaken to study the vase life of tinted spikes of gladiolus cultivar. White prosperity harvested at different stages. The experiment comprised of two factors of which the first one was spikes treated with eight food dyes with 5% concentration and time of immersion for two hours and the second one was various stages of harvest. The results revealed that spikes harvested at stage 1(1-2 basal florets show colour) had a higher vase life of 8.16 days, maximum time of 8.56 days to fully loose colour after tinting, lowest mean transpirational loss of 29.17 g. spike-1, highest mean diameter of florets ( 9.21 cm), least decrease of 4.52 g/100g mean percentage of lipids and least decrease of 12.59 g/100g mean percentage of proteins. Benefit cost ratio of tinting the spikes with Lemon yellow, Violet and Orange red was 1.34 while with Kesar yellow, Kalakatta, Blue and Apple green was 1.29. Thus it can be concluded that for tinting the spikes of gladiolus cv. White Prosperity, with greater vase life harvesting the spikes at stage 1(1-2 basal florets show colour) was found to be optimum.

A Perceptual Analysis of Standard Safety, Fluorescent, and Neon Colors

Twenty-six standard safety colors specified by the American National Standards Institute (ANSI), International Standards Organization (ISO), and the Federal Highway Association (FHWA) were compared to seven fluorescent and neon colors on perceived hazard and perceived importance. Results indicated that the fluorescent orange, ANSI red, fluorescent yellow, FHWA red, fluorescent yellow green, and ISO red were the highest rated colors on perceived hazard. ANSI red, FHWA red, ISO red, fluorescent orange, fluorescent yellow, and fluorescent yellow green were rated the highest on perceived importance. The implications of these findings and the potential use of fluorescent colors in product warnings are discussed.

Cesarferreiraite, Fe2+Fe23+(AsO4)2(OH)2{middle dot}8H2O, from Eduardo mine, Conselheiro Pena, Minas Gerais, Brazil: Second arsenate in the laueite mineral group

Cesarferreiraite, Fe2+Fe23+(AsO4)2(OH)2·8H2O, is a new laueite-group mineral (IMA 2012-099) of triclinic symmetry, from Eduardo pegmatite mine, Conselheiro Pena municipality, Minas Gerais, Brazil. Intimately associated minerals are pharmacosiderite, scorodite, and earlier arsenopyrite, and probably cesarferreiraite replaces the latter. It occurs as fibrous-to-tabular aggregates up to 2 mm. Single crystals, up to 10 μm long with a thickness of about 1–2 μm, are elongated along [001] and flattened on (100). The fibers have almost rectangular cross-section apparently bound by the {100} and {010} pinacoid forms. Color and streak are pale to greenish yellow. Luster is vitreous; individual crystals are transparent and masses are translucent. Cleavage is distinct, presumably on {010} and {100}. Calculated density is 2.934 g/cm3. The mineral is biaxial (+), n (min) = 1.747(3), n (max) = 1.754(3) (589 nm). IR spectrum of cesarferreiraite is unique and can be used for the identification of the mineral. Chemical composition ( n = 4, WDS, calculated for the condition Fe2+:Fe3+ = 1:2, H2O for the ideal structural formula, wt%) is: FeO 11.50, Fe2O3 25.56, CaO 15.41, As2O5 33.51, H2O 26.01, total 100.12. The empirical formula (based on 18 O apfu) is Fe2+0.98Fe3+1.96[(AsO4)1.79(PO4)0.31](OH)1.52·8.08H2O. The strongest eight X-ray powder-diffraction lines [ d in A( I )( hkl )] are: 9.85(95)(010), 6.35(100)(001), 3.671(29)(121), 3.158(32)(130), 2.960(39)(022), 2.884(35)(131), 2.680(29)(211), and 2.540(23)(210). Unit-cell parameters refined from powder data indexed by analogy with related laueite-group minerals (space group: P 1) are: a = 5.383(2), b = 10.363(3), c = 6.878(2) A, α = 96.42(4), β = 109.19(3), γ = 102.30(2)°, V = 347.1(2) A3, and Z = 1. Gladstone-Dale compatibility is −0.020 (excellent). Cesarferreiraite is the arsenate analog of ferrolaueite.

Colorimetric Characteristics of Metamerism of Yellowish Green Peridot

Fifty-one yellowish-green color 5mm×7mm oval faceted peridots are experimented by Color i5 to test their color parameters, and concept of metamerism is introduced into this article, to analyze the effects of color parameters on the color appearance of peridots. SPSS analysis indicates: wavelength λ has no correlation with metamerism index MI, but excitation purity Pe has significant correlation with MI (rPe×MI=0.826, 0.01), means with the increase of excitation purity, the color appearance of peridot tend to be more unsteady and change more with the illumination conversion. Simultaneously, metamerism index MI increase with increasing chromaticity C* and lightness L* (rC*×MI=0.979, rL*×MI=0.889, 0.01), means the change of color appearance increase with illumination conversion. In conclusion, when the yellowish-green of peridot is more saturate and brighter, the effect of illumination on color appearance is greater.

Characterization of Chemical Constituents of Tinospora cordifolia

Tinospora cordifolia of the family Menispermaceae, known as Amrita Guduchi (Sanskrit), is widely used in folk Ayurvedic medicine and by Rasayanas to improve the immune system and body resistance against infections. Amrita is a constituent of several preparations like Amritarishtam, Dhanvantaramtailam, Cheriya rasnadi kashayam, and Valia marmagulika. However, practitioners consider Tinospora cordifolia as a genuine source for Amrita [1, 2]. The term, Amrita meaning divine nectar, is attributed to this drug in recognition of its capacity to impart youthfulness, vitality, and longevity to the consumer. The drug consists of dried stem with bark intact. It is widely used in general as a tonic, anticancer, antiulcer, antipyretic, antihepatitis, immunomodulatory, antioxidant, hypoglycemic, antineoplastic, cardiotonic, antibacterial, antimicrobial, antiinflammatory, antiarthritic, and analgesic, and it has diuretic properties [3]. Tinospora cordifolia is a large, glabrous, deciduous climbing shrub. It is distributed throughout the tropical Indian subcontinent and China, ascending to an altitude of 300 m, and is commonly known as Giloya, Gurcha, and Amrita (Hindi), which is a Hindu mythological term that refers to the heavenly elixir that has saved celestial being from old age and kept them eternally young. It is known as Tinospora Gulancha in English. The stems of Tinospora cordifolia are rather succulent with filiform fleshy aerial roots from the branches. The bark is creamy white to gray, deeply left spirally, the space in between being spotted with large rosette-like lenticels. The leaves are membranous and cordate. The flowers are small, yellow or greenish yellow. There are auxiliary and terminal racemes or racemose panicles; the male flowers are clustered and the female flowers are usually solitary. The drupes are ovoid, glossy, succulent, red, and pea sized. Flowers grow during the summer. The seed are curved. Fruits are fleshy and single seeded and grow during the winter [4, 5]. Preparation of Plant Material. The stems of Tinospora cordifolia were collected during summer 2008 from Pousara, Katni (M.P.) India. The plant was identified by Dr. K. P. Sahu, Department of Botany, Govt. Autonomous Model Science College, Jabalpur (M.P.), India, and a voucher Specimen No. 16 from the collection dated 28 November 2008 was kept in the Department of Botany Autonomous Model Science College, Jabalpur (M.P.) India. The stems powder (7 kg) was subjected to hot extraction with MeOH by a Soxhlet extractor, and after evaporation of the solvent by a rotary evaporator, 8 g of crude extract was obtained [6, 7]. Isolation and Purification of Compounds. A small portion of MeOH extract dissolved in petroleum ether and solution was spotted on TLC plates. Then TLC plates were run trough various solvent systems and viewed individually under UV light. By classical chromatographic separations the compounds of the MeOH extract were separated by n-hexane–ethyl acetate (8:2), n-hexane–ethyl acetate (1:1), ethyl acetate–water (7:3), and finally with ethyl acetate–water (1:1). Nine fractions were found homogeneous on TLC plates using n-hexane–ethyl acetate (8:2), petroleum ether–ethyl acetate (8:2), and petroleum ether–methanol (8:2) solvent systems. These fractions were crystallized and named 1–9. Mayer Test for Alkaloids. Mercury dichloride (13.5 g) and KI (50 g) are dissolved in 1 L of water; this is used as a test for alkaloids, with which it gives a white precipitate. The first six compounds gave a positive test for alkaloids [8]. Salkowski Test for Triterpenoids. Five mL of each extract was mixed in 2 mL of chloroform, and conc. H2SO4 (3 mL) was carefully added. A reddish brown coloration of the interface was formed,which showed a positive result for the presence of triterpenoids for the three remaining compounds [9].

Introduction to Colorimetric Analysis for Assessment of Carotenoid Pigments in Squash Germplasm

Carotenoids of squash play an important role in human health by acting as sources of provitamin A or as protective antioxidants. Among the 60 accessions of squash germplasm, fluorescent yellow and yellow types of flesh color got the highest count, followed by the orange, whitish yellow and greenish yellow. The redness and yellowness values of the flesh powder ranged from -2.45 to 86.09 and from 13.77 to 39.80, respectively. While the lightness and the total color difference values of flesh color varied from 67.64 to 86.09 and from 19.77 to 51.79, respectively. Colorimetric values of redness and yellowness showed positive correlation, and the correlation coefficient (r) was as high as 0.7386. The five accessions represented each flesh color types, IT195043 (orange), IT136696 (fluorescent yellow), IT186365 (yellow), IT137963 (whitish yellow), and IT180449 (greenish yellow). The total amount of carotenoid contents was in the order of orange color (104.64 mg/100 g), greenish yellow color (70.82 mg/100 g), fluorescent yellow color (32.41 mg/100 g), yellow color (8.73 mg/100 g), and whitish yellow color (4.73 mg/ 100 g). Both lutein and β-carotene were the predominant pigments of carotenoids, and lycopene was only separated and identified in the orange color flesh. According to the results, colorimetric analysis can aid breeders interested in increasing carotenoid content in squash, which could be accurately measured using a simple, reliable, and cost- and labor-efficient method for the evaluation of carotenoid pigments.

New nickel-uranium-arsenic mineral species from the oxidation zone of the Belorechenskoye deposit, Northern Caucasus, Russia: II. Dymkovite, Ni(UO2)2(As3+O3)2·7H2O, a seelite-related arsenite

A new arsenite mineral species dymkovite, ideally Ni(UO 2 ) 2 (As 3+ O 3 ) 2 ·7H 2 O (IMA no. 2010-087), was found at the Belorechenskoye deposit, Adygea Republic, Northern Caucasus, Russia. It is a supergene mineral associated with rauchite, annabergite, and goethite in cavities of a dolomite vein with primary uraninite (pitchblende), nickeline, and gersdorffite. Dymkovite forms long-prismatic, lath-shaped to acicular crystals (≤0.5 mm long, ≤0.05 mm thick), which are elongated along [010]. They are combined in sprays or open-work, chaotic groups up to 1.5 mm across; crusts up to 2 × 2 mm 2 and up to 0.05–mm-thick also occur. Dymkovite crystals are transparent and bright yellow, whereas crusts are translucent and light yellow to light greenish-yellow. The luster is vitreous. The mineral is brittle, the Mohs’ hardness is ca. 3. Cleavage was not observed. D calc is 3.806 g cm −3 . Dymkovite is optically biaxial (−), α = 1.625(2), β = 1.735(5), γ = 1.745(3), 2 V meas = 20(10)°, 2 V calc. = 32°. Dispersion is strong, r > v . Pleochroism is strong: X = very pale yellowish-green, Y ≈ Z = light greenish yellow. In the IR spectrum, bands of As 3+ O 3 anions are strong, whereas bands of As 5+ O 4 anions are very weak. The average chemical composition (electron microprobe) is (in wt%): MgO = 1.11, FeO = 0.24, NiO = 5.40, ZnO = 0.23, As 2 O 3 = 19.57, P 2 O 5 = 0.58, UO 3 = 59.43, H 2 O calc = 13.44, total = 100.00. The empirical formula, calculated on the basis of 17 O apfu, is: (Ni 0.69 Mg 0.26 Fe 0.03 Zn 0.03 ) ∑1.01 U 1.97 (As 3+ 1.88 P 0.08 ) ∑1.96 O 9.94 ·7.06H 2 O. Dymkovite is monoclinic, space group C 2/ m , a = 17.99(3), b = 7.033(7), c = 6.633(9) A, β = 99.62(11)°, V = 827(3) A 3 , Z = 2. The crystal structure was refined from single-crystal X-ray diffraction data ( R 1 = 0.063). The structure is based upon the [(UO 2 )(As 3+ O 3 )] − sheets formed by chains of edge-sharing [UO 7 ] pentagonal bipyramids and (As 3+ O 3 ) triangular pyramids, which are linked through hydrogen bonds involving disordered [Ni(H 2 O) 6 ] 2+ octahedra and additional H 2 O molecules in the interlayer. The strongest lines of the powder X-ray pattern [ d in A ( I )( hkl )] are: 8.93(100)(200), 4.463(34)(111, 400), 3.523(23)(020), 3.276(21)(220), 3.008(26)(11-2), 2.846(27)(112, 221, 31-2). Dymkovite is a Ni-dominant, almost arsenate-free analogue of seelite, Mg(UO 2 ) 2 [(As 3+ O 3 ) 1.4 (As 5+ O 4 ) 0.6 ]·7H 2 O. The mineral is named in honor of the Russian mineralogist Yuriy Maksimovich Dymkov (b. 1926), a specialist in U mineralogy, the geology of U deposits, and problems of mineral formation, who was one of the first researchers of the U ores of the Belorechenskoye deposit.

Tsilaisite, NaMn3Al6(Si6O18)(BO3)3(OH)3OH, a new mineral species of the tourmaline supergroup from Grotta d'Oggi, San Pietro in Campo, island of Elba, Italy

Tsilaisite, NaMn3Al6(Si6O18)(BO3)3(OH)3OH, is a long-expected new mineral of the tourmaline supergroup. It occurs in an aplitic dike of a LCT-type pegmatite body from Grotta d’Oggi, San Pietro in Campo, island of Elba, Italy, in association with quartz, K-feldspar, plagioclase, elbaite, and schorl. Crystals are greenish yellow with a vitreous luster, a white streak, and show no fluorescence. Tsilaisite has a Mohs hardness of approximately 7; it is brittle with a sub-conchoidal fracture, and has a calculated density of 3.133 g/cm3. In plane-polarized light, tsilaisite is pleochroic, O = pale greenish yellow, E =very ale greenish yellow; it is uniaxial negative, ω = 1.645(5), Ɛ = 1.625(5). Tsilaisite is rhombohedral, space group R3m, a = 15.9461(5), c = 7.1380(3) Å, V = 1571.9(1) Å3, Z = 3. The strongest eight ‑raydiffraction lines in the powder pattern [d in Å(I)(hkl)] are: 3.974(100)(220), 2.942(94)(122), 2.570(79) (051), 2.034(49)(152), 4.205(41)(211), 6.329(22)(101), 2.377(21)(003), and 1.592(21)(550). Analysis by a combination of electron microprobe, secondary ion mass spectrometry, and optical absorption spectroscopy gives SiO2 = 36.10(3), TiO2 = 0.32(4), Al2O3 = 37.10(5), MnO = 9.60(10), CaO = 0.09(4), Na2O = 2.11(7), K2O = 0.03(1), F = 0.79(3), B2O3 = 10.2(6), Li2O = 0.8(1), H2O = 3.1(2), sum 99.95 wt%. The unit formula is X(Na0.67⃞0.30Ca0.02K0.01)Y(Mn2+1.34Al1.14Li0.54Ti0.04)ZAl6T(Si5.94Al0.06)B2.91O27V(OH)3W(OH0.39F0.41O0.20). The structure, refined also taking into account the positional disorder of the O1 and O2 anions, converged to statistical indices R1 for all reflections of about 2%. The resulting site populations indicate that the Z site is occupied by Al and that the Y site is dominated by Mn2+. Aluminum is incorporated at Y through two types of substitutions: YAl+WO2- → YMn2++WOH, which has the result of replacing OH at the W site by O2-, and Y(Al+Li)+WF → 2YMn2++WOH, which relates fluor-elbaite to the tsilaisite component. Infrared absorption spectra measured in the principal OH-stretching region were interpreted on the basis of local arrangements consistent with the short-range bond-valence requirements. A compositional trend from fluor-elbaite to tsilaisite is observed in samples from Elba Island. The occurrence of tsilaisite is very rare in nature, as a consequence of both the requirement of extraordinary petrogenetic conditions and limited structural stability.