Prismatic Crystals Research Articles

Gypsum crystal morphologies in lake sediments for paleoclimate reconstructions: a case study in Fuente de Piedra playa-lake (Málaga)

Gypsum (CaSO4∙2H2O) is one of the most common evaporitic minerals on Earth. Its crystals exhibit diverse morphologies that can provide insights into their depositional environment. We analyzed the morphologies of gypsum deposits in a 14 m sedimentary sequence of Fuente de Piedra playa-lake (Málaga, Spain) to link its variations to sedimentary facies and changes in the past lake level. Precipitation of primary prismatic crystals prevailed during lake highstand periods. In contrast, lenticular gypsum crystals are consistently present throughout the entire core and do not seem to be related to specific lake levels. An exception are macro-lenticular crystals, which seem to be correlated with dry periods and high salinity water. Subrounded gypsum grains, eroded from former primary crystals, are also abundant along the sequence and usually concentrate in facies related to stages of lake agitation during highstand periods. Gypsum is generally absent during lowstand periods, which may indicate relatively high dissolve organic matter or, more likely, less interaction of the lake with the saline groundwater aquifer beneath. Our results suggest that the occurrence of some gypsum morphologies can be used to infer paleo-lake levels.

Understanding the anatomical diversity of leaves in the Aspicarpoid clade: New insights for Malpighiaceae systematics

The Aspicarpoid clade represents a strongly supported group within the Stigmaphylloid lineage. The group is composed of four neotropical genera: Aspicarpa Rich., Gaudichaudia Kunth, Janusia A.Juss. and Peregrina W.R.Anderson. In this study, we studied the utility of leaf anatomy characters to support groups recovered in molecular phylogenies and define synapomorphies that can be used in future infra- and supra-generic classifications. Camarea axillaris A.St.-Hil. (1823: 10) and Cottsia Dubard & Dop (1908: 20) were used as outgroups for comparison. Dry leaf samples were re-hydrated, sectioned, stained, and analyzed using a microscope and a stereomicroscope. Characters such as presence and absence of glands, their location and morphotype, petiole and midrib contour, presence of trichomes, accessory bundles, vascular system organization and mesophyll type were utilized for species comparison, showing high taxonomic value for the group. Leaf glands, accessory bundles, sheath extension in the mesophyll and presence of druses and prismatic crystals were the most valuable characters in an evolutionary approach for the clade. Our work confirms the power of leaf anatomy as a taxonomic and evolutionary tool in Malpighiaceae Juss. (1789: 252), as well as its contribution to the delimitation of phylogenetic groups in the Aspicarpoid clade.

Radio-transparent celsian ceramics modified with glass in a pseudoternary system BaO–Al2O3–SiO2: synthesis, microstructure, thermal and physical properties

The article presents the results of the study of radio-transparent celsian ceramics, in which part of the components were introduced using eutectic glass of the pseudoternary BaO–Al2O3–SiO2 system. The bonding of the components of the experimental glass into the celsian phase was realized according to the principle of reactive structure formation by adding the missing components (crystalline fillers). In this case, the obtained dense sintered water-resistant ceramic, the only crystalline phase in the composition of which is the monoclinic form of celsian, which forms a microhomogeneous structural matrix of the material. Celsian is represented by distinct prismatic crystals of tetragonal and hexagonal shape. The size of celsian crystals increases from 3–5 m to 7–10 m with increasing the content of eutectic glass. The developed celsian ceramic has a set of enhanced physical and thermal properties: zero water absorption and open porosity, mechanical compressive strength (up to 157 MPa), refractory index is 1540–15800C. Celsian ceramic is characterized by a coefficient of linear thermal expansion of 3410–7 0C–1, which provides a sufficiently high thermal shock resistance of 7000C. In terms of the level of relative dielectric permittivity (5.5) and dielectric losses (0.0005) at a frequency of 1010 Hz, the developed ceramic meets the requirements for ultra-high-frequency radio-transparent materials for aviation and rocket technology, which operate under conditions of high-speed high-temperature heating.

Detailed Pharmacognostical Standardisation and Phytochemical Analysis of Whole Plant of <i>Tephrosia barber</i> — An Endemic Novel Medicinal Plant

Background: Tephrosia barberi J. R. Drumm. is a perennial herb belonging to the Fabaceae family. Aim: The present research work is focused on carrying out the pharmacognostic standardisation and primary phytochemical analysis of the whole plant of T. barberi. Methods: The morphology, microscopy, powder microscopy, quantitative analysis of leaf constants, fluorescence analysis and physio-chemical parameters were included in the pharmacognostical work for the whole plant followed WHO prescribed quality control methods. The primary phytochemical analysis is carried out for powder with different solvent extracts using standard procedure. Results: The study reveals that the microscopical character of the whole plant of T. barberi includes the presence of cork, phloem fibres, xylem vessels, starch grains, tracheids, unicellular warty trichomes, anamocytic type of stomata and prismatic type calcium oxalate crystal sheath. The total ash, acid insoluble ash, water soluble ash value, sulphated ash, and loss on drying were quantified as physiochemical parameters, which were observed by 3%, 1%, 2%, 5% and 8%, respectively, using T. barberi dry powder. Under daylight, long and short UV, extracts of the whole plant and with various reagents were seen as various fluorescent reflection shades, which showed satisfactory results. Additionally, the primary phytochemical analysis of different extracts of T. barberi showed the presence of alkaloids, flavonoids, steroidal glycosides, polyphenols and terpenoids. Conclusion: All these findings ensured that the whole plant profile for T. barberi could be accomplished, which may provide proper identification and probable to minimise the adulteration of other plant species. Furthermore, the primary phytochemical screening study would be useful to carry out the isolation of phytoconstituents and their therapeutic potency in future.

In situ boro-mullite phase formation in Glass–Ceramic glazes: Anatase–rutile phase transformations and microstructure properties

‘‘Boro-mullite’’ is the name for mullites produced through the synthesis of boron-rich material and playing a critical role in producing high-performance materials. Also, the stability of the anatase phase in the glaze and against temperature has been addressed and improved by many studies. In situ boro-mullite crystals generated using various glass-ceramic glaze compositions that contain TiO2 and their impact on the transformation of anatase into a rutile phase were examined in this study. Additionally, the samples' water absorption, bulk density, apparent porosity and shrinkage, Vickers hardness, and optical properties were evaluated at various Al2O3 and B2O3 amounts at 700 °C, 800 °C, 900 °C, 1000 °C and 1100 °C. X-ray diffraction analysis revealed that as the temperature and Al2O3 ratio rose, it triggered the boro-mullite phase formation. On the other hand, increasing the Al2O3 ratio led to a rise in the samples' sintering temperature and delayed the anatase to rutile phase transformation. Furthermore, the presence of corundum crystals retarded the anatase crystal size growth during the remodelling process of the conversion of anatase to rutile. While the increase in the B2O3 ratio sharpened the peaks of albite crystals, the formation of rutile crystals accelerated with the increase in temperature and caused inhibition of albite formation. The albite phase's presence facilitated the creation of the liquid phase and achieved the 0.010 % water absorption and 0 % apparent porosity values as well the highest bulk density and microhardness with 2.476 g/cm3 and 550 H V. The yellowness (+b∗) values were found to be the highest at 1100 °C where the rutile crystals reached their maximum size. The anatase-rutile conversion is postponed and the increase in the yellowness value is prevented by the glaze's formation of boro-mullite. FESEM-EDS analysis showed that the temperature was the driving force in the transformation of acicular boro-mullite crystal into highly acicular prismatic needle crystal and spherical anatase crystals into the rod shape rutile.

Mathematical Modeling of Sorptive Extraction of Lithium Chloride from Lithium-containing Brine of the Aral Sea Region

Introduction The article presents the results of chemical and physicochemical analysis of initial lithium-containing hydromineral raw materials and sorbent based on bentonite clay with titanium oxide addition. Methods It is established that the mineral is montmorillonite group and kaolinite according to the results of the analysis of the microstructure and elemental composition of bentonitic clay of the Darbazinsky deposit. Brine is characterized by the change of lithium chloride content in the range of 403- 1001 mg/l. Physical and mechanical characteristics of the obtained sorbents based on bentonite clay and titanium oxide additive are characterized by a high mechanical strength of 5.31 MPa, density of up to 2,6 g/cm3, and specific surface area of 1572 cm2/g. The technological parameters of sorption extraction of lithium chloride from lithium-containing hydromineral raw materials were optimized using the system analysis “STATISTICA” developed by StatSoft company. It is established that to increase the rate of lithium chloride extraction from brine, it is necessary to maintain the rate of brine flow within 8 l/min at maximum humidity of solution output up to 43g/m3 on the basis of the obtained volumetric graphical dependencies. Results The microstructure of the used sorbents with titanium oxide addition up to 20% is characterized by the predominance of lithium chlorides, which are represented by heap-shaped, prismatic crystals. Conclusion The maximum amount of lithium chloride in the form of clusters of light-white crystals of tabular shape on the surface of the sorbent is observed at increasing the content of titanium oxide up to 40%.

Freeze-thaw resistance and service life prediction of fly ash incorporated ultra-high ductility magnesium phosphate cement-based composites

To develop ultra-high ductility magnesium phosphate cement-based composites (UHDMC) suitable for cold areas and fully utilize solid waste, the effects of fly ash (FA) substitution and freeze-thaw cycles on the mechanical properties and freeze-thaw resistance of UHDMC specimens were explored. The mechanism of freeze-thaw damage was revealed by mercury intrusion porosimetry (MIP) and scanning electron microscope (SEM). Freeze-thaw damage model for UHDMC was established to predict its service life. The results showed that, after 300 freeze-thaw cycles, the compressive strength retention rate of the UHDMC specimens with FA substitution from 10 % to 30 % was above 88.7 %, and the tensile strain maintained above 3.48 %, still presenting the characteristics of multi-cracking and strain hardening. Meanwhile, after 600 freeze-thaw cycles, the mass loss rate and the dynamic elastic modulus of UHMPC specimens with FA substitution from 10 % to 30 % were below 1.38 % and above 81.1 %, respectively. The mechanical properties were mainly related to the total porosity and macropores. The effect of the water solubility of prismatic struvite-K crystals and the secondary hydration production of filamentous struvite potassium crystals on the matrix presented well explanation for the excellent freeze-thaw resistance of UHDMC specimens with FA substitution from 10 % to 30 %. At last, a freeze-thaw damage model for UHDMC specimens with FA substitution below 30 % based on the Weibull probability distribution function was established, predicting that their service life was up to 232 years in the northeastern of China.

Pleistocene Glacial Transport of Nephrite Jade from British Columbia, Canada, to Coastal Washington State, USA

Since prehistoric times, indigenous residents of southwest British Columbia, Canada, collected water-worn nephrite specimens from the gravel bars along the Fraser River, using the stone for the manufacture of tools that were widely traded with other tribes. Allochthonous nephrite occurs in another geologic setting. Late Pleistocene continental glaciers transported nephrite and many other rock types from western Canada to northwest Washington State, producing extensive sediment deposits that border the Salish Sea coast in Whatcom and Island Counties, Washington. This material was little utilized by indigenous residents, but “black jade” specimens are prized by modern collectors. The depositional history and mineralogy of this material has received little attention. X-ray diffraction and SEM/EDS analyses indicate that the Salish Sea “black jade” is a form of impure nephrite that probably originated from metamorphism of a mafic igneous parent material (metabasite). The texture consists of prismatic amphibole crystals (ferro-actinolite) set in a matrix rich in plagioclase feldspar. Pyrite inclusions are locally present. A second material, sometimes erroneously labelled “muttonfat jade” by amateur collectors, consists of an intermixture of quartz and sillimanite.

A New Mineral Calcioveatchite, SrCaB11O16(OH)5·H2O, and the Veatchite–Calcioveatchite Isomorphous Series

The new mineral calcioveatchite, ideally SrCaB11O16(OH)5·H2O, is a Ca-Sr-ordered analogue of veatchite. It was found at the Nepskoe potassium salt deposit, Irkutsk Oblast, Siberia, Russia in halite-sylvite and sylvite-carnallite rocks, with boracite, hilgardite, kurgantaite, hydroboracite, volkovskite, veatchite, anhydrite, magnesite, and quartz. Calcioveatchite forms prismatic or tabular crystals up to 1 × 1.5 × 3 mm3 and crystal clusters up to 3 mm across. It is transparent and colourless with vitreous lustre. Calcioveatchite is brittle, cleavage is perfect on {010}, the Mohs’ hardness is ca 2, Dmeas is 2.58(1), and Dcalc is 2.567 g cm−3. Calcioveatchite is optically biaxial (+), α = 1.543(2), β = 1.550(5), γ = 1.626(2), 2Vmeas = 30(10)°, and 2Vcalc = 35°. The average chemical composition (wt.%, electron microprobe, H2O calculated by stoichiometry) is: CaO 7.05, SrO 20.70, B2O3 61.96, H2O 10.22, and total 99.93. The empirical formula, calculated based on 22 O apfu = O16(OH)5(H2O) pfu, is Sr1.23Ca0.78B10.99O16(OH)5·H2O. Calcioveatchite is monoclinic, space group P21, a = 6.7030(3), b = 20.6438(9), c = 6.6056(3) Å, β = 119.153(7)°, V = 798.26(8) Å3, and Z = 2. Polytype: 1M. The strongest reflections of the powder XRD pattern [d,Å(I,%)(hkl)] are: 10.35(100)(020), 5.633(12)(110), 5.092(10)(120), 3.447(14)(060), 3.362(13)(101, 051), 3.309(38)(–102), 2.862(10)(012), and 2.585(19)(080). The crystal structure was solved based on single-crystal XRD data, R1 = 0.0420. Calcioveatchite (calcioveatchite-1M) is an isostructural analogue of veatchite-1M with the 11-fold cation polyhedron occupied mainly by Sr [Sr0.902(8)Ca0.098(8)] whereas the 10-fold polyhedron is Ca dominant [Ca0.686(7)Sr0.314(7)]. The chemical composition of veatchite from five localities in Russia (Nepskoe), Kazakhstan (Shoktybay and Chelkar in the North Caspian Region), and the USA (Tick Canyon and Billie Mine in California) was studied, and it is shown to exist in nature as a continuous, almost complete isomorphous series which extends from Ca-free veatchite, Sr2B11O16(OH)5·H2O, to calcioveatchite with the composition Sr1.14Ca0.87B10.99O16(OH)5·H2O.

Anatomical conservatism in the wood and bark of the species-rich Byrsonimoid clade (Malpighiaceae)

Abstract The byrsonimoids include approximately 152 species of trees and shrubs native to the Neotropical region. The clade is monophyletic and consists of three genera: Byrsonima, Blepharandra, and Diacidia. Byrsonima woods are among the most well-known within the Malpighiaceae due to their economic importance. Nonetheless, here for the first time we explore the interspecific stem anatomical diversity of Byrsonima, its similarities and differences to Blepharandra and Diacidia, and how the previously proposed taxonomic circumscriptions for the genus Byrsonima are reflected or not in their wood and bark anatomy. Using a newly reconstructed phylogeny for the Malpighiaceae focusing on the clade Byrsonimoid and a broad selection of species, we conducted phylogenetic comparative analyses to determine how wood and bark traits have evolved across evolutionary time. Our results indicate stem anatomical homogeneity within the clade, particularly in wood traits. On one hand, the presence of septate fibres and prismatic crystals in the rays distinguishes Byrsonima from other members of the clade, but on the other hand, wood and bark traits do not support the classical infrageneric classifications for the genus. The bark in byrsonimoids displays the entire range of variation known for sclerenchyma in this tissue, from cells that can be considered true fibres to fibre-sclereids and typical true sclereids. Ancestral character state reconstructions revealed that radial arrangement, septate fibres, thin heterocellular rays, marginal parenchyma, and prismatic crystals are ancestral traits within the clade, with homoplasy common within the group. These observations demonstrate anatomical conservatism within the Byrsonimoid clade, which might be either related to their proposed recent diversification or a highly effective set of positively selected features.

STUDY ON ANATOMICAL CHARACTERIZATIONOF EXOTIC SPECIES AMHERSTIA NOBILIS WALL

Amherstia nobilis, known as the Pride of Burma and colloquially referred to as Simshipa-vriksham, is a remarkable and rare tropical tree celebrated in Indian mythology, especially within the context of the epic Ramayana. Often dubbed the Queen of Flowering Trees. The species was named in honour of Lady Sarah Amherst, an early collector of Asian plants, and it stands as the sole representative of its genus. This study involves microscopic examination of various parts of the plant, revealing intricate details about its cellular structure, vascular arrangements, and overall morphology. Mature leaves of A. nobilis, for instance, have been analyzed micro-morphologically, with an average leaf area calculated. The leaves are characterized by numerous rubiaceous stomata, as hypostomatic. In the leaf midrib, the vascular area appears oval and vascular elements are U-shaped. The leaf lamina flanked by highly cutinized upper and lower epidermis layers. The palisade tissue is bi-layered, while the lower leaf lamina features loosely packed spongy layers with numerous vein bundles and large air spaces and contains starch grains. Histological examination of the rachis reveals an oval shape with a slightly thick-walled epidermis and hypodermis containing air cavities. The vascular region is well-differentiated withxylem elements in linear multiples. The secondary phloem elementspossess numerous prismatic crystals and patches of phloem fibers. In the mature stem, periderm formation, with a highly reduced cortical region containing chlorenchymatous cells. The vascular region comprises phloem tissues with patches of phloem fibers. The xylem is with large vessels arranged in linear multiples. The pith is highly reduced with included phloem elements. Wood anatomy reveals the vessels displaying paratracheal parenchyma distribution, appearing as aliform or eyelet type. The vessel elements are arranged in linear multiples, and the radial longitudinal section shows large vessel elements with bordered pits separated by end plates. The bark showed uni- and multi-seriate ray cells, long and narrow phloem parenchyma, and prismatic crystal deposits in phloem ray-parenchyma cells. The parenchyma cells are traversed by numerous phloem fibers, with starch granules deposited in phloem parenchyma. In conclusion, Amherstia nobilis, the Pride of Burma, exemplifies a unique combination of aesthetic appeal and complex anatomical structure, making it a subject of significant interest in botanical and horticultural research. Detailed histological and anatomical studies provide crucial insights into the species unique adaptations and structural features, underscoring the need for continued conservation efforts to protect this majestic and rare tropical tree.

Comparative Anatomical Analysis of Bark Structure in 10 Quercus Species.

Detailed anatomical features of bark are used and interpreted in plant taxonomy, phylogenetics, and other areas of plant science. However, the delicate nature of bark cells, combined with the difficulty of obtaining high-quality sections and reliable data, limits the potential for utilizing and processing bark. In this study, the anatomical structure of the bark of 10 Quercus species growing in Yunnan Province, China, was characterized in detail. The results indicate that the anatomical features of the barks of 10 Quercus spp. show a certain degree of consistency. Specifically, sieve tubes are distributed in solitary elements or in small groups, mostly as compound sieve plates containing 2-8 sieve areas, suggesting that Quercus spp. may occupy a conservative evolutionary position. Additionally, for the first time, this study reports the presence of simple sieve plates in the sieve tube elements of Quercus phloem. Each sieve tube element has a companion cell on one side. The companion cell strands contain 2-7 cells. Axial parenchyma is diffuse, with parenchyma strands typically consisting of 4-7 cells; druses are present within chambered crystalliferous cells. Phloem rays are of two distinct sizes and often exhibit dilatation and sclerification, and the ray composition consists of procumbent cells. Sclerenchyma is composed of fibers and sclereids, both of which contain prismatic crystals. Most of the fibers are gelatinous fibers, which are distributed in discontinuous tangential bands of about five cells in width. Sclereids appear in clusters. The presence of sclerenchyma provides mechanical support to the bark, reducing the collapse of the phloem. Periderm usually consists of around 10-30 layers of phellem, and Quercus acutissima and Q. variabilis can reach dozens or hundreds layers. The phelloderm typically consists of from two to five layers, with Q. variabilis having up to ten or more layers. The filling tissue of lenticels in all Quercus species is nonstratified (homogeneous) and largely nonsuberized. Overall, this study enriches our comprehension of Quercus bark anatomy, elucidating evolutionary patterns, functional adaptations, and ecological ramifications within this significant botanical genus.

STUDY ON ANATOMICAL CHARACTERIZATION OFCLERODENDRUM QUADRILOCULARE (BLANCO) MERR

Clerodendrum quadriloculare (Blanco) Merr., commonly called as the bronze-leaved Clerodendrum, shooting star, or Starburst bush, is native to New Guinea and Philippines. It coming under the family Lamiaceae.Traditionally, C. quadriloculare is used in Filipino folk medicine. Despite its traditional medicinal use, systematic anatomical studies on the plant are limited. Investigating its anatomical featuresare crucial for authenticating traditional claims, preventing adulteration, and distinguishing sibling species. Microscopic examination of C. quadrilocularereveals distinct superficial and anatomical characteristics. The leaf anatomy shows lower lamina comprises starch grains. The leaves exhibit anomocytic stomata. Numerous glandular dots are present on the epidermal peel. The midrib shows a thick cuticular epidermis with glandular hairs. The medulla features vascular bundles, with the outer phloem region having fibrous bands. The pith consists of small prismatic crystals. The petioles anatomy includes a thick-walled epidermis and numerous glandular trichomes. The vascular bundleswith brachysclereids as bundle caps. The stems transverse section reveals an outer periderm with lenticels. The outer edge of the secondary phloem contains fibers. The xylem vessels are linearly arranged and uni-bi seriate, with the presence of xylem parenchyma and fibers. The pith is thick-walled, with primary bundles intruding into it. The wood highlights tracheids and large vessel elements, with lateral vessel walls featuring bordered pits. The bark is well-deposited with starch granules. In conclusion, the anatomical study of C. quadriloculare provides a comprehensive understanding of its internal structure, contributing to the scientific validation of its traditional medicinal uses. The findings highlight the plants complex histological features, which are essential for its identification, potential medicinal applications, and conservation. This research underscores the importance of anatomical profiling in authenticating traditional knowledge and protecting valuable plant species from adulteration and misidentification.

High plasma magnesium and phosphorus levels and their correlation with struvite urolithiasis in buffaloes

BackgroundUrolithiasis is a common urinary tract disease in buffaloes, almost exclusively affects young males, and has significant economic and production impacts. We have investigated hemato-biochemical and urinary changes in an attempt to deduce their correlation with struvite urolithiasis in buffaloes. MethodsTen male buffalo calves with obstructive urolithiasis were used. Blood samples were used for hematology and elemental analysis. Urine samples were used for physico-chemical examination, microscopy, and elemental analysis. Uroliths were subjected to chemical functional group determination using the FTIR spectroscopy. ResultsThe mean neutrophil, leukocyte, and neutrophil-to-lymphocyte ratio was significantly (p < 0.05) higher in urolithic buffaloes than in healthy controls. The mean blood calcium and magnesium concentrations were significantly (p < 0.05) lower and higher in urolithic buffaloes than in healthy controls, respectively. Mean blood phosphorus concentration and calcium-phosphorus ratio were found to be non-significantly (p > 0.05) higher and lower in urolithic buffaloes than in healthy controls, respectively. The urine pH was highly alkaline. Multiple prismatic lid-shaped crystals, along with erythrocytes, leukocytes, and epithelial cells, were found in urine. The mean urinary magnesium and phosphorus concentrations were non-significantly (p < 0.05) higher in urolithic buffaloes than in healthy controls. A positive correlation of magnesium (r = 0.864, p = 0.001) and phosphorus (r = 0.849, p = 0.002) concentrations between the blood and urine was observed in urolithic buffaloes. The FTIR spectra of uroliths were similar to those of magnesium ammonium phosphate hexahydrate, MgNH4PO4·6H2O or struvite. ConclusionThe findings suggest that high plasma magnesium and phosphorus concentrations have a positive correlation with struvite urolithiasis in buffaloes.

Quality Studies on Cynometra iripa Leaf and Bark as Herbal Medicines.

Cynometra iripa Kostel. is a Fabaceae species of mangrove used in traditional Ayurvedic medicine for treating inflammatory conditions. The present study aims to establish monographic botanical and chemical quality criteria for C. iripa leaf and bark as herbal substances and to evaluate their in vitro antioxidant potential. Macroscopic and microscopic qualitative and quantitative analyses, chemical LC-UV/DAD-ESI/MS profiling, and the quantification of key chemical classes were performed. Antioxidant activity was evaluated by DPPH and FRAP assays. Macroscopically, the leaf is asymmetrical with an emarginated apex and cuneate base. Microscopically, it shows features such as two-layered adaxial palisade parenchyma, vascular bundles surrounded by 3-6 layers of sclerenchyma, prismatic calcium oxalate crystals (5.89 ± 1.32 μm) along the fibers, paracytic stomata only on the abaxial epidermis (stomatal index-20.15), and non-glandular trichomes only on petiolules. The microscopic features of the bark include a broad cortex with large lignified sclereids, prismatic calcium oxalate crystals (8.24 ± 1.57 μm), and secondary phloem with distinct 2-5 seriated medullary rays without crystals. Chemical profile analysis revealed that phenolic derivatives, mainly condensed tannins and flavonoids, are the main classes identified. A total of 22 marker compounds were tentatively identified in both plant parts. The major compounds identified in the leaf were quercetin-3-O-glucoside and taxifolin pentoside and in the bark were B-type dimeric proanthocyanidins and taxifolin 3-O-rhamnoside. The total phenolics content was higher in the leaf (1521 ± 4.71 mg GAE/g dry weight), while the total flavonoids and condensed tannins content were higher in the bark (82 ± 0.58 mg CE/g and 1021 ± 5.51 mg CCE/g dry weight, respectively). A total of 70% of the hydroethanolic extracts of leaf and bark showed higher antioxidant activity than the ascorbic acid and concentration-dependent scavenging activity in the DPPH assay (IC50 23.95 ± 0.93 and 23.63 ± 1.37 µg/mL, respectively). A positive and statistically significant (p < 0.05) correlation between the phenol content and antioxidant activity was found. The results obtained will provide important clues for the quality control criteria of C. iripa leaf and bark, as well as for the knowledge of their pharmacological potential as possible anti-inflammatory agents with antioxidant activity.

Microtextural evidence for the recrystallization of opal-A to quartz in epithermal veins: A case study from the McLaughlin deposit, California

High-grade ores in low-sulfidation epithermal deposits commonly consist of banded veins containing quartz as the most abundant gangue mineral. Previous studies suggested that at least some of the quartz has formed as a product of recrystallization from a noncrystalline silica precursor. Detailed petrographic studies confirm that high-grade veins from the <2.2 Ma McLaughlin deposit in California were originally entirely composed of opal-AG. The noncrystalline silica is isotropic in crossed-polarized light and consists of compacted microspheres that are up to several micrometers in size. In many bands of the high-grade veins, the thermodynamically unstable opal-AG has matured to quartz. The recrystallization of the noncrystalline silica resulted in the development of quartz and ore textures that mask the original conditions of vein formation. Incipient recrystallization of the opal-AG caused the formation of lepispheres consisting of opal-CT as well as the development of concentrically banded silica spheres. Continued maturation led to the growth of elongated quartz crystals or complexly shaped quartz aggregates in the cores of the concentrically banded silica spheres. Amalgamation of quartz crystals caused the development of mosaic quartz or flamboyant quartz. Ripening produced large prismatic quartz crystals, which are characterized by zones of feathery appearance. Fluid inclusions within the quartz formed through recrystallization are typically highly irregular in shape and show inconsistent liquid-to-vapor volumetric proportions, but assemblages with consistent ratios are also present. Bands rich in fluid inclusions occurring along former recrystallization fronts in prismatic quartz crystals resemble growth zones in zonal quartz. Recrystallization of the silica matrix resulted in grain coarsening of the ore minerals and encapsulation of ore minerals by quartz. In areas where recrystallization of the noncrystalline silica proceeded to completeness, the quartz textures could be easily misinterpreted to indicate that quartz growth occurred in open space with the ore minerals infilling vug spaces. Correct recognition of recrystallization textures has significant implications for paragenetic investigations on vein material from epithermal deposits as well as the design of fluid inclusion studies.

Pharmacognostic Studies on the Stem Bark of &lt;I&gt;Psidium guajava&lt;/I&gt; Linn

The macroscopic and microscopic characters of the stem bark of Psidium guajava Linn, are described. Due to earlier defoliation of the previous cork layers the whole bark seems to consist of secondary phloem topped by cork cells. Absence of cortical tissue isone of the chief diagnostic characters. The bark is characterised by the presence of prismatic crystals of calcium oxalate in smaller phloem parenchyma cells, fusiform medullary ray cells terminated by tapering apical cells and absence of cortical and phloem fibres.

Pharmacognostic Studies on the Stem Bark of &lt;i&gt;Streblus asper&lt;/i&gt; Lour.

The macroscopic and microscopic studies of the stem bark of Streblus asper Lour. are made. Macroscopic characters reveal that the outer surface of the bark has got longitudinal wrinkles with transverse channels. On drying the bark can be easily separated into two layers; the outer hard and the inner fibrous layer. Two types of stone cells, phloem fibres with broad lumen and large prismatic crystals of calcium oxalate are the chief diagnostic characters.

Savelievaite, Mg2CrO2(BO3), the first natural borate with species-defining Cr3+ and the ludwigite–savelievaite isomorphous series

AbstractThe new ludwigite-group mineral savelievaite, ideally Mg2Cr3+O2(BO3), was found in the chromitite body at the Malaya Kharamatalou river valley, Voikar–Syninskiy ultrabasic complex, Polar Urals, Russia. Savelievaite and Cr-enriched ludwigite occur in clinochlore veinlets and are associated with earlier magnesiochromite, spinel, chromite, pargasite, diopside, forsterite, serpentine, magnetite and pentlandite. Savelievaite forms prismatic, acicular or fibrous crystals up to 0.05 × 0.4 mm, usually assembled in radiating or chaotic clusters up to 1 × 1.5 mm across. It is opaque, black to greenish-black. The lustre is vitreous for prismatic crystals and silky for fibrous aggregates. D(calc.) = 3.91 g cm–3. Under the microscope in reflected light, savelievaite is grey, non-pleochroic, with weak bireflectance and anisotropism. The chemical composition (wt.%, EMPA, Fe2+:Fe3+ ratio by stoichiometry) is: MgO 34.88, FeO 10.83, NiO 0.36, B2O3 16.80, Al2O3 2.97, V2O3 0.21, Cr2O3 21.97, Fe2O3 12.40, TiO2 0.43, total 100.85. The empirical formula calculated on the basis of 5 O apfu is (Mg1.72Fe2+0.30Ni0.01)Σ2.03(Cr3+0.57Fe3+0.31Al0.12Ti0.01V3+0.01)Σ1.02B0.96O5. Savelievaite is orthorhombic, space group Pbam, a = 9.2631(6), b = 12.2298(8), c = 3.0104(2) Å, V = 341.04(4) Å3 and Z = 4. The strongest reflections of the powder X-ray diffraction pattern [d,Å(I)(hkl)] are: 5.101(100)(120); 2.551(90)(240); 2.524(88)(201); 2.163(36)(250); and 2.033(55)(321). The crystal structure was solved from single-crystal X-ray diffraction data and refined to R1 = 0.0405. Savelievaite is isostructural with ludwigite, Cr3+ is concentrated at the M4 site. The mineral is named in honour of the Russian petrologist and geologist Dr. Galina Nikolaevna Savelieva (b. 1936). Ludwigite, ideally Mg2Fe3+O2(BO3), and savelievaite form a continuous isomorphous series in which Cr3+ content varies from 0 to 0.60 apfu. Occurrences of Cr-enriched (&gt;1 wt.% Cr2O3) varieties of ludwigite are mainly related to ultrabasic complexes. The Cr-richest (&gt;10 wt.% Cr2O3) ludwigite–savelievaite-series members are found in chromite ores at the Voikar–Syninskiy complex and Volchiegorskoe and Tatishchevskoe deposits, both in the South Urals.

Pharmacognostic Studies on the Stem Bark of &lt;i&gt;Annona reticulata&lt;/i&gt; Linn.

The microscopic and microscopic characters of the stem bark of Annona reticulata Linn. are described. Groups of lignified phloem fibres with narrow lumen which seperate the phloem parenchyma in blocks, lignified stone cells, large prismatic crystals of calcium oxalate and simple as well as compound starch grains the latter with 2 to 4 components are the chief diagnostic characters.