|
Amethyst
Amethyst is a violet variety of quartz. The name comes from the Koine Greek αμέθυστος ''amethystos'' from α- ''a-'', "not" and μεθύσκω (Ancient Greek) / μεθώ (Modern Greek), "intoxicate", a reference to the belief that the stone protected its owner from drunkenness. Ancient Greeks wore amethyst and carved drinking vessels from it in the belief that it would prevent intoxication. Amethyst, a semiprecious stone, is often used in jewelry and is the traditional birthstone for February. Structure Amethyst is a purple variety of quartz (SiO2) and owes its violet color to irradiation, impurities of iron and in some cases other transition metals, and the presence of other trace elements, which result in complex crystal lattice substitutions.Michael O'Donoghue (2006), ''Gems'', Butterworth-Heinemann, 6th ed. The hardness of the mineral is the same as quartz, thus making it suitable for use in jewelry. Hue and tone Amethyst occurs in primary hues from a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lavender (color)
Lavender is a light shade of purple or violet. It applies particularly to the color of the flower of the same name. The web color called lavender is displayed at right—it matches the color of the very palest part of the lavender flower; however, the more saturated color shown below as '' floral lavender'' more closely matches the average color of the lavender flower as shown in the picture and is the tone of lavender historically and traditionally considered ''lavender'' by the average person as opposed to those who are website designers. The color lavender might be described as a ''medium purple'' or a ''light pinkish-purple''. The term ''lavender'' may be used in general to apply to a wide range of pale, light or grayish-purples but only on the blue side. Lilac is pale purple on the pink side. In paints, the color lavender is made by mixing purple and white paint. The first recorded use of the word ''lavender'' as a color term in English was in 1705. Historical develo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quartz
Quartz is a hard, crystalline mineral composed of silica ( silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO2. Quartz is the second most abundant mineral in Earth's continental crust, behind feldspar. Quartz exists in two forms, the normal α-quartz and the high-temperature β-quartz, both of which are chiral. The transformation from α-quartz to β-quartz takes place abruptly at . Since the transformation is accompanied by a significant change in volume, it can easily induce microfracturing of ceramics or rocks passing through this temperature threshold. There are many different varieties of quartz, several of which are classified as gemstones. Since antiquity, varieties of quartz have been the most commonly used minerals in the making of jewelry and hardstone carvings, especially in Eurasia. Quartz is the mineral definin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jewelry
Jewellery (British English, UK) or jewelry (American English, U.S.) consists of decorative items worn for personal adornment, such as brooches, ring (jewellery), rings, necklaces, earrings, pendants, bracelets, and cufflinks. Jewellery may be attached to the body or the clothes. From a western perspective, the term is restricted to durable Ornament (art), ornaments, excluding flowers for example. For many centuries metal such as gold often combined with gemstones, has been the normal material for jewellery, but other materials such as glass, shells and other plant materials may be used. Jewellery is one of the oldest types of archaeological artefact – with 100,000-year-old beads made from ''Nassarius'' shells thought to be the oldest known jewellery.Study reveals 'oldest jewellery' , ''BBC News'', June ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
February
February is the second month of the year in the Julian and Gregorian calendars. The month has 28 days in common years or 29 in leap years, with the 29th day being called the ''leap day''. It is the first of five months not to have 31 days (the other four being April, June, September, and November) and the only one to have fewer than 30 days. February is the third and last month of meteorological winter in the Northern Hemisphere. In the Southern Hemisphere, February is the third and last month of meteorological summer (being the seasonal equivalent of what is August in the Northern Hemisphere). Pronunciation "February" is pronounced in several different ways. The beginning of the word is commonly pronounced either as or ; many people drop the first "r", replacing it with , as if it were spelled "Febuary". This comes about by analogy with "January" (), as well as by a dissimilation effect whereby having two "r"s close to each other causes one to change. The ending of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birthstone
A birthstone is a gemstone that represents a person's period of birth that is usually the month or zodiac sign. Birthstones are often worn as jewelry or as a pendant necklace. History of birthstones Western custom The first century historian Josephus believed there was a connection between the twelve stones in Aaron's breastplate (signifying the tribes of Israel, as described in the Book of Exodus), the twelve months of the year, and the twelve signs of the zodiac. Translations and interpretations of the passage in Exodus regarding the breastplate have varied widely, with Josephus himself giving two different lists for the twelve stones. George Frederick Kunz argues that Josephus saw the breastplate of the Second Temple, not the one described in Exodus. St. Jerome, referencing Josephus, said the Foundation Stones of the New Jerusalem ( Revelation 21:19–20) would be appropriate for Christians to use. In the eighth and ninth century, religious treatises associating a particu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prasiolite
Prasiolite (also known as green quartz, green amethyst or vermarine) is a green variety of quartz. Since 1950, almost all natural prasiolite has come from a small Brazilian mine, but it has also been mined in the Lower Silesia region of Poland. Naturally occurring prasiolite has also been found in the Thunder Bay area of Canada. , the only commercial mine producing prasiolite is in Brazil. Most prasiolite sold is used in jewellery settings, where it can substitute for far more expensive precious gemstones. Prasiolite is a rare stone in nature; artificial prasiolite is produced by heat treatment of amethyst. Most amethyst will turn yellow or orange when heated, producing citrine, but some amethyst will turn green when treated. Currently, almost all prasiolite on the market results from a combination of heat treatment and ionizing radiation. Green quartz is sometimes incorrectly called green amethyst, which is not an acceptable name for the material according to Federal Tra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mohs Scale Of Mineral Hardness
The Mohs scale of mineral hardness () is a Qualitative property, qualitative ordinal scale, from 1 to 10, characterizing scratch hardness, scratch resistance of various minerals through the ability of harder material to scratch softer material. The scale was introduced in 1812 by the German geologist and Mineralogy, mineralogist Friedrich Mohs, in his book ''"Versuch einer Elementar-Methode zur naturhistorischen Bestimmung und Erkennung der Fossilien"''; it is one of several definitions of Hardness comparison, hardness in materials science, some of which are more quantitative. The method of comparing hardness by observing which minerals can scratch others is of great antiquity, having been mentioned by Theophrastus in his treatise ''On Stones'', , followed by Pliny the Elder in his ''Natural History (Pliny), Naturalis Historia'', . The Mohs scale is useful for identification of minerals in the field, but is not an accurate predictor of how well materials endure in an industrial s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gemstone Irradiation
Gemstone irradiation is a process in which a gemstone is artificially irradiated in order to enhance its optical properties. High levels of ionizing radiation can change the atomic structure of the gemstone's crystal lattice, which in turn alters the optical properties within it. As a result, the gemstone's color may be significantly altered or the visibility of its inclusions may be lessened. The process, widely practised in jewelry industry, is done in either a nuclear reactor for neutron bombardment, a particle accelerator for electron bombardment, or a gamma ray facility using the radioactive isotope cobalt-60. These irradiation processes have enabled the creation of gemstone colors that do not exist or are extremely rare in nature. Radioactivity and regulations The term ''irradiation'' is a broad one, which covers bombardment by subatomic particles as well as the use of the full range of electromagnetic radiation, including (in order of increasing frequency and decreasi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Artigas, Uruguay
Artigas () is the capital of the Artigas Department of Uruguay. Its name comes from that of the national hero, José Gervasio Artigas, who fought for the emancipation of the River Plate, and sought to create a federative nation from these colonies. As of the census of 2011, it is the eleventh most populous city in the country. Location The city is located on the border with Brazil, separated only by a bridge from the town Quaraí of the state Rio Grande do Sul of Brazil. It is the farthest city from Uruguay's capital Montevideo, being away. History It was founded on 12 September 1852 by Don Carlos Catalá as the town of San Eugenio del Cuareim. On 5 September 1884 it became capital of the department. It was renamed Artigas and its status was elevated from ''villa'' (town) to ''ciudad'' (city) on 31 August 1915. Economy Artigas is a centre for trading grain crops (primarily maize) with Argentina and Brazil. The railroad station and, since 1973, airport are focused on this co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gemstone Irradiation
Gemstone irradiation is a process in which a gemstone is artificially irradiated in order to enhance its optical properties. High levels of ionizing radiation can change the atomic structure of the gemstone's crystal lattice, which in turn alters the optical properties within it. As a result, the gemstone's color may be significantly altered or the visibility of its inclusions may be lessened. The process, widely practised in jewelry industry, is done in either a nuclear reactor for neutron bombardment, a particle accelerator for electron bombardment, or a gamma ray facility using the radioactive isotope cobalt-60. These irradiation processes have enabled the creation of gemstone colors that do not exist or are extremely rare in nature. Radioactivity and regulations The term ''irradiation'' is a broad one, which covers bombardment by subatomic particles as well as the use of the full range of electromagnetic radiation, including (in order of increasing frequency and decreasi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Koine Greek
Koine Greek (; Koine el, ἡ κοινὴ διάλεκτος, hē koinè diálektos, the common dialect; ), also known as Hellenistic Greek, common Attic, the Alexandrian dialect, Biblical Greek or New Testament Greek, was the common supra-regional form of Greek spoken and written during the Hellenistic period, the Roman Empire and the early Byzantine Empire. It evolved from the spread of Greek following the conquests of Alexander the Great in the fourth century BC, and served as the lingua franca of much of the Mediterranean region and the Middle East during the following centuries. It was based mainly on Attic and related Ionic speech forms, with various admixtures brought about through dialect levelling with other varieties. Koine Greek included styles ranging from conservative literary forms to the spoken vernaculars of the time. As the dominant language of the Byzantine Empire, it developed further into Medieval Greek, which then turned into Modern Greek. Literary Koi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicon
Silicon is a chemical element with the symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic luster, and is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic table: carbon is above it; and germanium, tin, lead, and flerovium are below it. It is relatively unreactive. Because of its high chemical affinity for oxygen, it was not until 1823 that Jöns Jakob Berzelius was first able to prepare it and characterize it in pure form. Its oxides form a family of anions known as silicates. Its melting and boiling points of 1414 °C and 3265 °C, respectively, are the second highest among all the metalloids and nonmetals, being surpassed only by boron. Silicon is the eighth most common element in the universe by mass, but very rarely occurs as the pure element in the Earth's crust. It is widely distributed in space in cosmic dusts, planetoids, and planets as various forms of silicon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
