Wavelength UV Radiation Research Articles

Mitigating the oxidative stress caused by UV-B in date palm seedlings: efficacy of salicylic acid and ascorbic acid application

Abstract The date palm is one of the plants whose growth is being affected by global warming through harmful wavelengths of UV radiation. The protective role of salicylic acid (SA) and ascorbic acid (AsA) at physiological (100 and 200 mg l–1) levels was assessed under UV-B (8 hrs day–1) stress in the development and physiological adaptation of date palm seedlings. Three months after treatment with different concentrations of SA and AsA, their effects on growth criteria, pigment content, oxidation stress markers, and enzyme antioxidant activities were studied. Results revealed that both SA and AsA increased the seedling height, leaf width, and dry weight, decreased the level of malondialdehyde and hydrogen peroxide, and increased membrane stability, thereby alleviating oxidant injury. Furthermore, activities of antioxidant enzymes such as peroxidase and ascorbate peroxidase have been upregulated, thereby enhancing the seedlings’ tolerance against stress. The results suggest that foliar SA and AsA application could be an efficient way to alleviate the UV-B radiation stress damage in young date palm plants, therefore providing a possible approach to improving crop resilience in increasingly harsh environmental conditions.

Near-Surfaces and Bulk Modification of Silicone Rubber under UV- and Vacuum UV-Irradiation Using Excimer and Hg Lamps.

The surface properties of silicone rubber can be modified by irradiation with light from the vacuum ultraviolet (VUV) spectral range of less than 200 nm. After VUV-irradiation at 185 nm with a low-pressure mercury (Hg) lamp, a reduction in residual-dust-coverage (PA fibers) of up to 80% was found. At the same time, the long wavelength UV-radiation at 254 nm of the Hg lamp causes a reduction in the optical transmission properties of the silicone bulk. The near-surface and bulk modification of optically highly transparent silicone rubber was analyzed using XPS, ATR, transmission measurements, and investigations into the reduction of the residual-dust-coverage. A comparison was made between a Hg lamp and an excimer lamp at 172 nm. The results provide valuable information for selecting the appropriate irradiation source, depending on the desired spectral range for a given application. The results indicate that excimer lamps should be preferred for optical applications in the UV-spectral range, while Hg lamps are equally suitable for applications in the visible spectral range despite low transmission losses of less than 0.5%. The irradiation dose data were obtained using a ray tracing simulation as part of these investigations to overcome limitations of UV-sensors, such as their accelerated aging and angular dependence.

Photochemical processes to cellular DNA damage by UV radiation of different wavelengths: biological consequences

UV radiation of sunlight induces in cellular DNA of different organisms photochemical reactions, which may lead to the development of series biological responses to arising lesions, including apoptosis, mutagenesis, and carcinogenesis. The chemical nature and the amount of DNA lesions depend on the wavelength of UV radiation. Photons of UV radiation in the region B (UVB, 290–320 nm) cause the production of two main defects, namely, cyclobutane pyrimidine dimers and, with a less yield, pyrimidine (6-4) pyrimidone photoproducts; their formation is the result of the direct UVB photon absorption by DNA bases. Photons of UV radiation in the region A (UVA, 320–400 nm) induce only cyclobutane dimers that can be formed by triplet-triplet energy transfer from cellular chromophores, absorbing photons of this UV region, to DNA thymine bases. UVA is much more effective than UVB in the sensitized oxidatively lesion formation in DNA such as single strand breaks and oxidized bases; among those, 8-oxo-dihydroguanine is the most frequent since it can be produced from several oxidation processes. In recent years, multiple papers, reporting novel, more detailed information about molecular mechanisms of photochemical reactions underlying the formation of different lesions in DNA were published. The present review mainly aims at summarizing and analyzing data contained in these publications, particularly regarding oxidative reactions that are initiated by reactive oxygen species and radicals generated by potential endogenous photosensitizers such as pterins, riboflavin, protoporphyrin IX, NADH, and melanin. The role of specific DNA photoproducts in genotoxic processes induced in living systems by UV radiation of different wavelengths, including human skin carcinogenesis, is discussed.

Photocaging of amino acids and short peptides by arylidenethiazoles: mechanism, photochemical characteristics and biological behaviour.

A series of fluorophores based on the (5-methyl-4-phenylthiazol-2-yl)-3-phenylacrylonitrile (MPTA) core were designed and synthesised for photocaging of amino acids and peptides. The photophysical characteristics of these compounds and their hybrids with biomolecules were thoroughly investigated through a joint experimental, spectral and computational approach. The photorelease ability of the obtained amino acids-MPTA and peptides-MPTA hybrids was studied under various conditions, including different UV irradiation wavelength and power, and solvents. The main reaction products were identified using high-performance liquid chromatography combined with high-resolution mass spectrometry. Photo uncaging kinetics was quantitatively studied using absorption spectroscopy. The mechanism of photorelease of amino acids and peptides was elucidated through quantum mechanical calculations, which were also used for the exploration of photophysical properties of the excited states, and photodissociation energetics quantification. Relationships between the structure of fluorophores and photodissociation characteristics were estimated, and fluorophores with the good uncaging characteristics (biomolecule photoreleasing yield, uncaging rate, and effectiveness) were identified. Cell viability assays using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide or MTT showed a low cytotoxicity of the hybrids. Confocal microscopy revealed the easy penetration of the hybrids into living cells and their selective accumulation in the endoplasmic reticulum, lipid droplets and mitochondria, depending on their chemical structure.

Investigation of Spectral and Optical Properties of Color Polarization LensesInvestigation of Spectral and Optical Properties of Color Polarization LensesInvestigation of Spectral and Optical Properties of Color Polarization Lenses

Polarized lenses are recommended because exposure to intense sunlight damages cellular function and photoreceptor structures in the eyes. Polarized lenses filter all wavelengths of UV radiation and most of the reflected glare due to strong reflections depending on the angle of incidence of sunlight and environmental factors. The wavelength of mineral glass in the horizontal and vertical direction (~550nm) is 16.64% for (CF1) and 13.21% for (CF2). There is a sudden drop of 27.87 at 729nm in CF2 and a sudden increase to 58.80 at 730nm in CF1. Absorbance values at 730nm are 0.21 with a decrease in AF1 and 0.54 with an increase in AF2. CF2 is polarized. To determine how the structure of the lens material affects light transmittance and absorbance, the light transmittances of smoked mineral and organic lenses of the same color are 16.64 for the mineral lens and 22.47 for the organic lens at (~550nm) wavelength. Maximum transmittance is 81.25 for mineral lens and 85.73 for organic lens. For night vision, at (~507nm) wavelength, it is 19.35 for mineral lens and 25.00 for organic lens. At (~550nm) wavelength, absorbance values are 0.78 for mineral lens and 0.62 for organic smoked lens. In the study, the effect of color factor on the light transmittance and absorption of organic smoked, brown and green polarized lenses was investigated. Light transmittance at 550 nm wavelength is 22.47 in smoked, 13.48 in brown and 14.32 in green. Absorbance at 550 nm wavelength is 0.62 in smoked, 0.94 in brown and 0.82 in green lens. Since dark lenses do not allow high light transmission, smoked color should be chosen for good vision in the visible light region. Brown color should be preferred if dark glasses should be used in situations where bright light is intense. In the 507nm wavelength of color polarized lenses, smoked is 25.00, brown is 11.45 and green is 16.94. Smoked should be chosen for night vision.

Presenting technological workflows

Presenting technological workflows

Continuous-Flow Synthesis of Cyclobutenes Using LED Technology

AbstractCyclobutenes are highly strained ring systems of considerable synthetic interest that can be accessed via cycloaddition reactions between alkenes and alkynes. However, their traditional preparation relies on photochemical [2+2] cycloadditions that exploit low-wavelength UV radiation emitted from inefficient medium-pressure Hg lamps. This paper reports on the development of a modern approach using a high-power LED set-up emitting at the boundary of UV-A and visible light in conjunction with a continuous-flow reactor. The resulting flow process renders a series of cyclobutenes from maleimides and various commercial alkynes. This provides a more energy-efficient approach that is readily scalable to access multigram quantities of cyclobutenes in high chemical yields and short residence times. The value of these products is exemplified by flow-based hydrogenations yielding highly substituted cyclobutanes which represent sought after building blocks in modern medicinal chemistry programs.

Bio-based light-healing isocyanate-free polyurethanes derived from carbonated soybean oil and coumarin

ABSTRACT In response to environmental concerns and restrictions on isocyanate-based materials, researchers and the coatings industry are focused on developing eco-friendly isocyanate-free polyurethanes. This article introduces a novel class of environmentally-friendly, initiator/catalyst-free, UV-curable, self-healing non-isocyanate polyurethanes (NIPUs) synthesized from bio-based carbonated soybean oil (CSO) and non-toxic coumarin. The synthesis of these polymers is based on using a photo-reactive coumarin that undergoes a reversible [2 + 2] cycloaddition upon exposure to the wavelength of UV light. UV-curable three coumarin-terminated isocyanate-free polyurethane prepolymers were synthesized using CSO and three different amines and epoxy coumarin. Subsequently, a set of cross-linked NIPU polymers were obtained with exposure of 365 nm UV irradiation. The photo-reversible nature of these polymers was investigated in response to various wavelengths of UV radiation. Additionally, their self-healing ability and the thermal and mechanical properties of NIPU coatings were studied using optical microscopy, thermogravimetric analysis, differential scanning calorimetry, and a universal testing machine. The outcomes demonstrate that this polyurethane has the potential to provide a sustainable alternative to isocyanate-based materials. Two examples of stimulated healing are given, that of healing a scratch and the other being the healing of a sample that has been mechanically stressed to failure in a tensile mode.

UV radiation sensitivity of bacteriophage PhiX174 - A potential surrogate for SARS-CoV-2 in terms of radiation inactivation

<abstract> <p>To minimize health risks, surrogates are often employed to reduce experiments with pathogenic microorganisms and the associated health risk. Due to structural similarities between the enveloped RNA-viruses SARS-CoV-2 and Phi6, the latter has been established as a nonpathogenic coronavirus surrogate for many applications. However, large discrepancies in the UV log-reduction doses between SARS-CoV-2 and Phi6 necessitate the search for a better surrogate for UV inactivation applications. A literature study provided the bacteriophage PhiX174 as a potentially more suitable nonpathogenic coronavirus surrogate candidate. In irradiation experiments, the sensitivity of PhiX174 was investigated upon exposure to UV radiation of wavelengths 222 nm (Far-UVC), 254 nm (UVC), 302 nm (broad-band UVB), 311 nm (narrow-band UVB) and 366 nm (UVA) using a plaque assay. The determined log-reduction doses for PhiX174 were 1.3 mJ/cm<sup>2</sup> @ 222 nm, 5 mJ/cm<sup>2</sup> @ 254 nm, 17.9 mJ/cm<sup>2</sup> @ 302 nm, 625 mJ/cm<sup>2</sup> @ 311 nm and 42.5 J/cm<sup>2</sup> @ 366 nm. The comparison of these results with published log-reduction doses of SARS-CoV-2 in the same spectral region, led to the conclusion that the bacteriophage PhiX174 exhibits larger log-reduction doses than SARS-CoV-2, nevertheless, it is a better UV-surrogate at 222 nm (Far-UVC), 254 nm (UVC) and 302 nm (UVB) than the often applied Phi6.</p> </abstract>

Periodate-based advanced oxidation processes for wastewater treatment: A review

The current review presents the analysis of the methods of periodate activation and its implementation as an advanced oxidation process for water and wastewater treatment focusing on the bio-resistant organic pollutants. Periodate activation methods were classified into homogeneous activation methods (activation by ultraviolet radiation, ultrasound, microwaves, thermal energy and hydrogen peroxide) and heterogeneous activation methods (photocatalytic activation, activation by granular activated carbon, transition metals, and their compounds, as well as metal nanoparticles). The mechanisms of generating the main reactive species in the periodate-based advanced oxidation processes were discussed. The influence of experimental conditions such as pH, temperature, concentrations of the pollutant, periodate ions, catalyst, the wavelength of UV radiation, and the presence of coexisting inorganic anions on the efficiency of oxidative degradation of organic compounds using periodate-based advanced oxidation processes was analyzed. It was found that the efficiency of periodate activation increases with operation in a near-acidic or neutral medium, using a lower initial concentration of pollutant and optimum catalyst loading as well as optimal IO4- concentration. Overall, the presented analysis of the disadvantages and advantages of periodate-based advanced oxidation processes indicated the promise in industrial wastewater treatment with synergism based on using combination approaches. The most optimum approach for industrial-scale implementation appears to be the activated periodate using an ultrasonic field combined with solid particles such as the granular activated carbon or transition metals and their compounds.

Exploration for UV Aging Characteristics of Asphalt Binders based on Response Surface Methodology: Insights from the UV Aging Influencing Factors and Their Interactions

• Provide a new insight for exploring the UV aging mechanism of asphalt binders. • Explore the effects of some potential influencing factors and their interactions on the UV aging characteristics of asphalt binders with RSM method. • Characterize the micro properties of asphalt binders irradiated by UV light with different wavelengths through some microscopic experiments. To explore the UV aging characteristics of asphalt, effects of potential influencing factors as well as their interactions on asphalt’s properties were investigated with the aid of Response Surface Methodology (RSM). Four influencing factors, including ultraviolet irritation wavelength, irritation intensity, asphalt film thickness, and aging temperature, were selected as the response variables of RSM. And complex shear modulus aging index G*AI , DSR function aging index DAI and fatigue factor aging index FAI were selected as the responses’ values. Then, the Central Composite Design (CCD) model of RSM was adopted to establish the statistical models to analyze the effects of different variables on asphalt’s UV aging behaviors. On this basis, aging degree of asphalt under ultraviolet irradiation with different wavelengths was analyzed emphatically with Fourier Transform Infrared Spectroscopy (FTIR) and Atomic Force Microscope (AFM) tests. Meanwhile, method for speeding up the efficiency of asphalt UV aging test by reducing the asphalt film was also proposed. Test results show that UV aging rate of asphalt increases gradually with the decreasing of asphalt film and the increasing of radiation intensity and aging temperature; among them, the effect of asphalt film thickness is the greatest, while that of aging temperature is the smallest. In addition, radiations with different wavelength have different effects on UV aging behaviors of asphalt, and asphalt irradiated by UV-340 to UV-360 has the highest aging degree, which can be further proved by FTIR and AFM test results. Interactions between different factors will also affect the UV aging characteristics of asphalt, and the results are related to the types of asphalt. However, interaction between UV radiation wavelength and asphalt film thickness all have the significant effects on the UV aging behaviors of base asphalt and SBS modified asphalt. Decreasing the asphalt film thickness can effectively increase the UV aging rate of asphalt. Thus, the aging time can be appropriately reduced on the basis of thinner asphalt film, so as to improve the test efficiency. And finally, it can be found that two processes may exist during the UV aging process of asphalt, namely molecular excitation process and chemical bond breaking process. Under the two actions, unstable chemical bonds in asphalt will reach the excited state or break, and combine easily with the oxygen atom and then generate some polar oxygen-containing functional groups, thus causing the decline of asphalt’s properties.

The comparison of Fenton and photo-Fenton oxidation as a primary unit process for the treatment of raw textile wastewaters.

The Fenton and photo-Fenton oxidation processes (FOP and PFOP) are usually applied as a secondary unit process, and direct usage of both processes is critical in textile wastewater treatment. There is seldom study on the direct application of the FOP or PFOP showing the treatment of raw textile industry wastewaters. This study demonstrates the application and comparison of both FOP and PFOP as single units separately for the treatment of wastewater in a textile industry producing woven fabrics. In both processes, the highest treatment efficiency was achieved at pH3. Chemical oxygen demand (COD), suspended solids (SS), and color parameters in FOP reduced from 1341 to 254 mg/L, 99.5 to 19.9mg/L, and 1396 to 97.7 Pt-Co, respectively. Separately, in the PFOP, 365-nm wavelength UV radiation sources have been used. In PFOP, the same parameters were reduced from 715 to 42.9mg/L, 90 to 9mg/L, and 2080 to 83.2 Pt-Co, respectively. These results were obtained at 0.7g Fe2+/L and 2mM H2O2 concentrations in both studies. PFOP can meet the textile industry receiving environment discharge standards of many countries, especially in Turkey. The use of PFOP as a single unit is possible in the treatment of textile industry wastewater without primary precipitation. The findings in this study may be practical for the adaptation of the processes on the field scale. PRACTITIONER POINTS: There is seldom study on the direct application of Fenton or photo-Fenton processes as a single unit to raw textile wastewaters This study shows the application of the Fenton or photo-Fenton processes as single units for the treatment of raw wastewater in a textile industry Results of both processes in this study meet the discharge standards of many countries Evaluations of efficiencies of both processes were achieved This study may be the focus of attention of treatment plant operators and researchers.

Application of electro-Fenton and photoelectro-Fenton processes for the degradation of contaminants in landfill leachate

Worldwide, most solid waste ends its life in landfill sites, which have a significant environmental impact in several respects. In particular, rainfall over landfill sites results in the production of an aqueous leachate containing compounds having low biodegradability, high toxicity, and a high organic load. For this reason, this study aims to investigate the applicability of electro-Fenton (EF) and photoelectro-Fenton (PEF) processes as alternative for treating a local landfill effluent with high organic content (chemical oxygen demand (COD) = 2684.7 mg-O2 L −1) in a continuous-flow reactor (using, for first time, this kind of system with higher electrodes area of 35 cm2) using boron-doped diamond anode (Nb/BDD) and a carbon felt cathode (FC) electrodes. The effects of current density j (30, 60 and 90 mA cm−2) and UV radiation wavelength (UVA and UVC) were studied to evaluate the treatment efficiency as well as the energy consumption. Results clearly showed that, the best efficiencies removing organic matter, in terms of COD, were about 66%, 68% and 89% with an energy consumption of only 19.41, 17.61 and 17.59 kWh kg COD−1 for EF, PEF-UVA and PEF-UVC respectively, at 90 mA cm−2 after 4 h of operation. The treatment of this kind of effluent produced organic and inorganic by-products, the acetic and formic acids as well as NO2−, NO3−, and NH4+, being assessed their concentrations.

Recent advances in self-powered and flexible UVC photodetectors.

Ultraviolet-C (UVC) radiation is employed in various applications, including irreplaceable applications in military and civil fields, such as missile guidance, flame detection, partial discharge detection, disinfection, and wireless communication. Although most modern electronics are based on Si, UVC detection technology remains a unique exception because the short wavelength of UV radiation makes efficient detection with Si difficult. In this review, recent challenges in obtaining ideal UVC photodetectors with various materials and various forms are introduced. An ideal photodetector must satisfy the following requirements: high sensitivity, fast response speed, high on/off photocurrent ratio, good regional selectivity, outstanding reproducibility, and superior thermal and photo stabilities. UVC detection is still in its infancy compared to the detection of UVA as well as other photon spectra, and recent research has focused on different key components, including the configuration, material, and substrate, to acquire battery-free, super-sensitive, ultra-stable, ultra-small, and portable UVC photodetectors. We introduce and discuss the strategies for fabricating self-powered UVC photodetectors on flexible substrates in terms of the structure, material, and direction of incoming radiation. We also explain the physical mechanisms of self-powered devices with various architectures. Finally, we present a brief outlook that discusses the challenges and future strategies for deep-UVC photodetectors.

Contribution Ultra Violet Radiation On Degradation Of Biodegradable Base Oil

Increasing environmental awareness led to the development of environmentally harmless lubricants made by biodegradable materials. Biodegradable lubricants are suitable for various kinds of application, one of the promising usages is for railways. Oils or greases are applied for railways or points to keep sufficient friction coefficient or to avoid wear damage. These lubricants are “once-through” lubricants, and never recovered but defused into the earth’s surface. The oxidation of lubricants on the railways will take place because of the sunlight effect. The solar radiation at the top of earth’s atmosphere contains a significant amount of UV radiation of shorter wavelength, and therefore higher energy. This study shows that the UV-B radiation can deteriorate rapeseed oil immediately. It is showed by the results of peroxide value, total acid number and molecular weight distribution are increased with oxidation time.

Photocrosslinking of Adventitial Collagen in the Porcine Abdominal Aorta: A Preliminary Approach to a Strategy for Prevention of Aneurysmal Rupture

This study was aimed at generating data for designing a potential method to prevent the rupture of the abdominal aortic aneurysm (AAA). We found that the mechanical strength and stiffness of blood vessel walls was enhanced by the crosslinking of adventitial collagen through a photochemical process promoted by ultraviolet-A (UV-A) radiation. The experiments were carried out on samples isolated from 25 normal porcine aortas. The adventitial layer was separated from the other layers and exposed to UV radiation of 365-nm wavelength, in the presence of a riboflavin compound as the photosensitizer. Mechanical testing of 30 specimens, prior to and after exposure, indicated an increase in both strength (ultimate stress) and stiffness (Young’s modulus) of the adventitial specimens following irradiation. The crosslinking process also led to an enhanced resistance to experimental collagenolysis, as determined on six specimens. At this phase of conceptual design, we suggest that by applying this method to an aneurysmal dilated wall region, the stabilization of tunica adventitia may delay or prevent the rupture of the aneurysm and, with further investigation and refinement, can become a therapeutic strategy for arresting the progression of AAA.

Light-driven self-assembly of cyanostilbene derivative with reversible chirality in aqueous media

In summary, we presented a design strategy for a chiral, amphiphilic, and photoswitchable molecule, using cholesterol, sulfonate, and cyanostilbene. The molecule could self-assemble to the trans-isomer in aqueous solution, which is accompanied by strong CD signals. Both trans- and cis-isomers are thermally stable, and the high conversion photoswitching between the trans- and cis-isomers with good fatigue resistance and reversibility, can be achieved using different wavelengths of UV irradiation. Furthermore, the optical chirality-CD was also modulated by UV irradiation. According to the TEM images and dynamic light scattering data, the photoswitching process involves self-assembly/disassembly from approximately 150 nm spherical particles to 18 nm irregular particles. We proposed a rational strategy using light-driven self-assembly for a molecular photoswitch in which optical chirality can be modulated by light irradiation in aqueous media.

UV radiation increases mortality and decreases the antioxidant activity in a tephritid fly

AbstractUltraviolet (UV) radiation has been widely used to monitor insects and conduct surface sterilizations at 365 nm and 254 nm wavelengths, respectively. The global increase in the use of UV light has raised concerns about environmental impacts and effects on non‐target organisms. We, therefore, examined the effects of three UV radiation wavelengths (365 nm, 308 nm and 254 nm) on the survival and antioxidant activities of a tephritid fruit fly, Bactrocera dorsalis. Exposure to UV radiation significantly increased B. dorsalis cohort mortality and the duration of pre‐oviposition. Moreover, the application of UV‐B and UV‐C significantly decreased egg laying. The activities of antioxidant enzymes were irreversibly decreased by UV‐A, UV‐B and UV‐C radiation. Decreases in catalase (CAT), superoxide dismutases (SOD) and glutathione‐S‐transferases (GST) activity were observed at both immediately after exposure and also at 120 h after exposure. However, while peroxidase (POD) activity was decreased immediately after UV‐B and UV‐C radiation, the activity had recovered at 120 h post‐exposure. These results demonstrate UV‐dependent decreases in the activities of antioxidant enzymes are associated with decreased B. dorsalis survival rates. While UV radiation can, therefore, be harmful to non‐target organisms, it is a potential strategy for integrated pest management.

The effect of UV-C radiation on the durability of 3D printed plastic parts in disinfectant devices

The usage of far or hard ultraviolet radiation in wavelength 200 – 280 nm or shortly UV-C disinfectors are becoming more and more popular due to their universal ability to fight against bacteria and viruses. It is well known that according to DIN 5031-7, both UV-A and UV-B radiation from sunlight have clear influence on the mechanical and visual properties of plastic parts, but the influence of intensive artificial UV-C is not so widely investigated. As the UV-C is in the shorter end of the UV radiation wavelength spectrum and is completely absorbed by the ozone layer and atmosphere, it is not possible to see the influence of it in everyday life. But in the equipment where the artificial UV-C radiation wavelength is used as a disinfectant, and probably in the open space, the influence of UV-C could be remarkable. Recently, there has been increasing interest in the food industry to avoid contamination in the food packing process. The global COVID-19 coronavirus pandemic has amplified this interest and has forced authors to run a set of tests with printed plastic parts. This paper analyses the outcome of those tests including two different printing directions and two different surface paints. The study shows that there is considerable influence of UV-C radiation on mechanical and aesthetic properties of 3D SLS printed PA12 parts. However, the influence can be diminished by use of appropriate paints.

Investigation of recently discovered common green opals from Anosy (Madagascar)

The physical, chemical and gemological properties of recently discovered common green opals from Anosy (South-Eastern Madagascar) have been investigated using different analytical methods such as standard optical and gemological analyzes, X-ray powder diffraction (XRPD), Scanning Electron Microscopy (SEM), Micro-Raman Spectroscopy and Laser Ablation Microprobe (LA-ICP-MS). Anosy opals have a yellowish green color with a light yellowish rim, translucent / opaque diaphaneity with greasy luster, red oxide spots and are inert to long and short wavelength UV radiation (366–254 nm). The values for refractive index and specific gravity range between 1.435–1.460 and 2.03-2.07, respectively. According to XRPD and Raman analyses, the opals are CT type with tridymite more abundant than cristobalite and also contain clay minerals (saponite). Iron and, subordinately, V and Cu appear the main chromophores that determine the green-yellowish color, while Ni and Cr are very subordinate. Other detected trace elements are Mg, Al, Ca, K, and Na. The high contents of Ba are noteworthy since this element is rarely reported in opals worldwide. SEM observations show three types of structures already observed in the CT opals: homogeneous and very fine microspheres, lepispheric cauliflower structures and globular aggregates of different sizes formed by laminae.