Готові списки джерел за темами / Precious opal

Добірка наукової літератури з теми "Precious opal"

Автор: Grafiati

Опубліковано: 10 грудня 2022

Оновлено: 29 січня 2023

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями

Оберіть тип джерела:

Зміст

Статті в журналах
Дисертації
Книги

Ознайомтеся зі списками актуальних статей, книг, дисертацій, тез та інших наукових джерел на тему "Precious opal".

Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.

Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.

Статті в журналах з теми "Precious opal"

Bellacera, Carole. "The Precious Opal." Appalachian Heritage 18, no. 4 (1990): 56–58. http://dx.doi.org/10.1353/aph.1990.0029.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Bootkul, Duangkhae, and Sawet Intarasiri. "Development of Glass-Ceramics from Soda Lime Silica Glass Waste by Direct Sintering Method for Opal Imitation." Key Engineering Materials 751 (August 2017): 397–402. http://dx.doi.org/10.4028/www.scientific.net/kem.751.397.

Повний текст джерела

Анотація:

Natural opal, an amorphous, hydrous form of silica (SiO2-n-H2O), has been one of the favored precious gemstones for many centuries. Though beautiful, opal is very fragile and is damaged quite easily. Thus, opals of all varieties have been synthesized experimentally and commercially. The objective of this project was to synthesize and to compare crystalline opals. In this work, the development of powder sintered glass ceramics process based on soda lime silica glass waste with metal oxide powder enable jewelry applications. The substantial viscous flow of the glass led to dense products for rapid treatments at relatively low temperatures (900–1,000°C), whereas glass/metal powder interactions resulted in the formation of color agent crystals, provide enhancing optical properties. Several techniques were applied for characterization of the ingots. The chemical analysis was performed by Energy Dispersive X-ray Fluorescence (ED-XRF). The mineralogical compositions of the samples were determined by X-ray diffraction analysis. Raman spectroscopy was applied for optical characterization. The results were compared with a natural common opal. The present investigation demonstrated that the common opal with both color and colorless appearance can be synthesized by the technique, as the crystalline phase of opal structure was identified by XRD measurement. There is a great potential for such materials with novel functionalities for artificial gemstone application, i.e. opal forming.

Стилі APA, Harvard, Vancouver, ISO та ін.

Ejigu, Assamen Ayalew, Desalegn Gezahegn Ketemu, Sisay Awoke Endalew, and Wudu Yimer Assen. "Characterization of Natural Precious Opal Using Modern Spectroscopic Techniques in Ethiopia: The Case from Delanta, South Wollo." Journal of Spectroscopy 2022 (August 24, 2022): 1–8. http://dx.doi.org/10.1155/2022/3194151.

Повний текст джерела

Анотація:

The purpose of this study was to conduct characterization of the Delanta natural opals obtained from different mining sites. Characteristics of opals mined from different geological locality were examined. Six opal samples were collected from the main mining sites found in different localities from Delanta district and characterized using Fourier infrared spectroscopy, scanning electron microscopy, X-ray diffraction, and inductively coupled plasma optical emission spectroscopy characterization techniques. The scanning electron microscope micrographs showed that all the samples have relatively semi-ordered (semi-crystalline) structural surface morphologies composed of tiny spherical particles. The performed X-ray diffraction analysis showed that the samples have main peaks at 20.0°, 21.72°, 36.9°, 44.0°, and 56.85° with 2 θ values between 10° and 60°. The five diffraction peaks are characteristic peak positions of opal-CT. The Fourier infrared spectroscopy data indicated that the prominent absorption bands for cristobalite at 620 and 520 cm−1 were absent from the spectrum. Instead, three bands in the low frequency region centered at 470, 791, and 1100 cm−1 were observed because of the absorptions of the silicate framework (Si-O) vibrations. red−1−1 Moreover,spectra feature of molecular water and silanol (Si-OH) groups with broadabsorption band centered around 3447 cm-1 andthe O-H stretching vibration of watermolecules and water bending vibration withan absorption band centered around 1634 cm-1were observed.. These values were consistently comparable with literature data. The inductively coupled plasma optical emission spectroscopy analysis showed that four main impurities (>500 parts per million) were Ca (∼1,750–4,730 parts per million), Al (∼1,990–4,319 parts per million, K (∼1,670–3,895 parts per million), and Na (∼595–3,723 parts per million). In general, this study revealed that all opal samples taken from six mining sites in Delanta district were found to be opal-CT as per the results of X-ray diffraction and Fourier infrared spectroscopy investigations.

Стилі APA, Harvard, Vancouver, ISO та ін.

Guo, Ying, Zhi Xuan Dai, and Hong Juan Sun. "The Correlation between Play-of-Color Effect and SiO₂ Cavities Size of Australian Blue Opal." Key Engineering Materials 492 (September 2011): 366–69. http://dx.doi.org/10.4028/www.scientific.net/kem.492.366.

Повний текст джерела

Анотація:

Its play-of-color effect of Australian opal makes it unique and much more precious than any other gemstones in the world. More than 50 Australian opals were chosen to conduct the experiments, including boulder and black opals with blue-green to blue-purple color. Spectropotometer Color i5 was used to analyze the color of opal samples with CIE L*a*b* uniform color space. Dominant wavelength was put into comparison with hue angle. SEM and AFM were the main means to analyze the internal structure of opal samples, and the diameter and size of cavities of SiO2 were measured and discussed. It is revealed that the hue angle of blue-purple opal is 302.15° with 449nm as its dominant wavelength, and so the size of SiO2 cavities in the sample is about 155.32nm; the hue angle of blue opals is between (256°, 286°) with the dominant wavelength between (471nm, 485nm), and so their size of SiO2 cavities is between (154.35nm, 182.54nm); the hue angle of blue-green opal is between (183°, 213°) with the dominant wavelength between (489nm, 500nm) and so their size of SiO2 cavities is between (172.95nm, 193.66nm). Besides, the diameter and size of SiO2 cavities were analyzed against the dominant wavelength, hue angle, lightness, and saturation to reveal their correlation. It is indicated that the diameter and size of SiO2 cavities are in positive correlation with the dominant wavelength, but negative correlation with the hue angle. As the diameter and size of SiO2 cavities grow, the dominant wavelength increases but the hue angle decreases. Also they are in positive correlation with lightness but their correlation with saturation was not discovered.

Стилі APA, Harvard, Vancouver, ISO та ін.

Stewart, A. M., Lewis T. Chadderton, and Brian R. Senior. "Self-assembly in the growth of precious opal." Journal of Crystal Growth 312, no. 3 (January 2010): 391–96. http://dx.doi.org/10.1016/j.jcrysgro.2009.09.042.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Potapov, V. V., and D. V. Kamashev. "Synthesis of precious opal in a hydrothermal solution." Glass Physics and Chemistry 32, no. 1 (January 2006): 89–98. http://dx.doi.org/10.1134/s1087659606010123.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Palgutová, Silvia, and Ľubomír Štrba. "Geoheritage of the Precious Opal Bearing Zone in Libanka Mining District (Slovakia) and Its Geotourism and Geoeducation Potential." Land 11, no. 12 (December 14, 2022): 2293. http://dx.doi.org/10.3390/land11122293.

Повний текст джерела

Анотація:

The northern part of the Slanské Vrchy Mountains, in Slovakia, within the territory of Dubnik Opal Mines, is considered to be the historical source of opal, including the opal known to the Romans. Dubnik precious opal mineralization originating from post-magmatic hydrothermal fluids based on its values should be recognized as an area of global importance. Geological processes that are connected to Neogene volcanic activity took place in the territory of the Dubnik Opal Mines and resulted in the formation of various geological products and processes represented by polymetallic mineral formation, opal formation, antimonite formation, and mineralization of the supergene stage, as well as the stratovolcano rock environment, which are of geoheritage significance. Remnants of intensive mining activity that took place during the past 2000 years provide opportunities for visitors to explore, study, and appreciate this unique geological heritage of international importance. However, geo-interpretation aimed at the general public (the largest group of potential visitors from sustainable geotourism development) and research on (geo)tourism and/or geoheritage for tourism purposes, as discussed in this paper, are lacking.

Стилі APA, Harvard, Vancouver, ISO та ін.

Dickson, B. L. "Which water formed Australian sediment-hosted precious and potch opal?" Australian Journal of Earth Sciences 66, no. 5 (March 24, 2019): 645–55. http://dx.doi.org/10.1080/08120099.2019.1572032.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Chauviré, Boris, Benjamin Rondeau, Francesco Mazzero, and Dereje Ayalew. "The Precious Opal Deposit At Wegel Tena, Ethiopia: FormationViaSuccessive Pedogenesis Events." Canadian Mineralogist 55, no. 4 (July 2017): 701–23. http://dx.doi.org/10.3749/canmin.1700010.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Pewkliang, B., A. Pring, and J. Brugger. "THE FORMATION OF PRECIOUS OPAL: CLUES FROM THE OPALIZATION OF BONE." Canadian Mineralogist 46, no. 1 (February 1, 2008): 139–49. http://dx.doi.org/10.3749/canmin.46.1.139.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Більше джерел

Дисертації з теми "Precious opal"

Concha, Alarcón Danilo, and Leiva Manuel Videla. "Sociedades anónimas acogidas al Artículo 10° transitorio de la Ley de Opas y su efecto en los precios accionarios." Tesis, Universidad de Chile, 2003. http://www.repositorio.uchile.cl/handle/2250/108197.

Повний текст джерела

Анотація:

Seminario para optar al título de Ingeniero Comercial
El objetivo de la presente investigación es determinar si aquellas empresas que manifestaron su voluntad de acogerse al artículo 10° transitorio de dicha ley (y las que no) entregaron de alguna manera información al mercado con esa decisión. De esta forma, a través del estudio de las variaciones de los precios de las acciones de aquellas empresas, queremos determinar si tuvieron retornos anormales dentro del período que rodeo a aquel anuncio.

Стилі APA, Harvard, Vancouver, ISO та ін.

Dowell, Katherine Margaret. "Precious opals in Australia." Master's thesis, 2008. http://hdl.handle.net/1885/148372.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Книги з теми "Precious opal"

Robertson, R. S. Geology of the Coober Pedy Precious Stones Field: Results of investigations, 1981-86. [Adelaide, South Australia]: Geological Survey of South Australia, 1990.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Cody, Andrew. Australian Precious Opal a Guide Book for Professionals. self Published, 1991.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Moody, Romi. She Is More Precious Than Jewels: Opal and Tourmaline. Independently Published, 2021.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

How To Identify Evaluate Select And Care For Matrix Opal Fire Agate Blue Chalcedony. International Jewelry Publications,U.S., 2014.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

The Precious Opals. Starwand Publications, 2014.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

The Precious Opals. USA: Starwand Publications, 2014.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

The Precious Opals. Starwand Publications, 2014.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Adams-Carter, Tina. Jim Stone and the Precious Opals. Independently Published, 2018.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Adams-Carter, Tina. Jim Stone and the Precious Opals. Independently Published, 2018.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Adams/Carter, Tina. Jim Stone and the Precious Opals. Independently Published, 2018.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Ми пропонуємо знижки на всі преміум-плани для авторів, чиї праці увійшли до тематичних добірок літератури. Зв'яжіться з нами, щоб отримати унікальний промокод!