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Æthiops Mineral
Cinnabar (; ), or cinnabarite (), also known as ''mercurblende'' is the bright scarlet to brick-red form of mercury(II) sulfide (HgS). It is the most common source ore for refining elemental mercury and is the historic source for the brilliant red or scarlet pigment termed vermilion and associated red mercury pigments. Cinnabar generally occurs as a vein-filling mineral associated with volcanic activity and alkaline hot springs. The mineral resembles quartz in symmetry and it exhibits birefringence. Cinnabar has a mean refractive index near 3.2, a hardness between 2.0 and 2.5, and a specific gravity of approximately 8.1. The color and properties derive from a structure that is a hexagonal crystalline lattice belonging to the trigonal crystal system, crystals that sometimes exhibit twinning. Cinnabar has been used for its color since antiquity in the Near East, including as a rouge-type cosmetic, in the New World since the Olmec culture, and in China since as early as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfide Mineral
The sulfide minerals are a class of minerals containing sulfide (S2−) or disulfide () as the major anion. Some sulfide minerals are economically important as metal ores. The sulfide class also includes the selenide mineral, selenides, the telluride mineral, tellurides, the arsenide mineral, arsenides, the antimonide mineral, antimonides, the bismuthinides, the sulfarsenides and the sulfosalts.http://www.minerals.net/mineral/sort-met.hod/group/sulfgrp.htm Minerals.net Dana Classification, SulfidesKlein, Cornelis and Cornelius S. Hurlbut, Jr., 1986, ''Manual of Mineralogy'', Wiley, 20th ed., pp 269-293 Sulfide minerals are inorganic compounds. Minerals Common or important examples include: * Acanthite *Chalcocite *Bornite *Galena *Sphalerite *Chalcopyrite *Pyrrhotite *Millerite *Pentlandite *Covellite *Cinnabar *Realgar *Orpiment *Stibnite *Pyrite *Marcasite *Molybdenite Sulfarsenides: *Cobaltite *Arsenopyrite *Gersdorffite Sulfosalts: *Pyrargyrite *Pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Refractive Index
In optics, the refractive index (or refraction index) of an optical medium is the ratio of the apparent speed of light in the air or vacuum to the speed in the medium. The refractive index determines how much the path of light is bent, or refraction, refracted, when entering a material. This is described by Snell's law of refraction, , where and are the angle of incidence (optics), angle of incidence and angle of refraction, respectively, of a ray crossing the interface between two media with refractive indices and . The refractive indices also determine the amount of light that is reflectivity, reflected when reaching the interface, as well as the critical angle for total internal reflection, their intensity (Fresnel equations) and Brewster's angle. The refractive index, n, can be seen as the factor by which the speed and the wavelength of the radiation are reduced with respect to their vacuum values: the speed of light in a medium is , and similarly the wavelength in that me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stoneware
Stoneware is a broad class of pottery fired at a relatively high temperature, to be impervious to water. A modern definition is a Vitrification#Ceramics, vitreous or semi-vitreous ceramic made primarily from stoneware clay or non-refractory fire clay.Arthur Dodd & David Murfin. ''Dictionary of Ceramics''; 3rd edition. The Institute of Minerals, 1994. This definition excludes stone vessels that are carving, carved from a solid chunk of rock (geology), stone. End applications of stoneware include tableware and ceramic art, decorative ware such as vases. Stoneware is fired at between about to . Historically, reaching such temperatures was a long-lasting challenge, and temperatures somewhat below these were used for a long time. It was developed independently in different locations around the world, after earthenware and before porcelain. Stoneware is not recognised as a category in traditional East Asian terminology, and much Asian stoneware, such as Chinese Ding ware for exampl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yangshao Culture
The Yangshao culture ( zh, c=仰韶文化, p=Yǎngsháo wénhuà ) was a Neolithic culture that existed extensively along the middle reaches of the Yellow River in China from around 5000 BC to 3000 BC. The Yangshao culture saw social and technological development in the region, with advancements in agriculture, architecture, and crafts. The culture is named after the Yangshao site, the first excavated site of this culture, which was discovered in 1921 in the town of Yangshao in western Henan by the Swedish geologist Johan Gunnar Andersson (1874–1960). The culture flourished mainly in Henan, as well as the neighboring provinces of Shaanxi and Shanxi. Recent research indicates a common origin and spread of the Sino-Tibetan languages with the Cishan, Yangshao and/or Majiayao cultures. Origins After the discovery of the Yangshao site in 1921, Johan Gunnar Andersson hypothesized, based on his analysis of the pottery patterns, that the Yangshao culture was originated fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
China
China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after India, representing 17.4% of the world population. China spans the equivalent of five time zones and Borders of China, borders fourteen countries by land across an area of nearly , making it the list of countries and dependencies by area, third-largest country by land area. The country is divided into 33 Province-level divisions of China, province-level divisions: 22 provinces of China, provinces, 5 autonomous regions of China, autonomous regions, 4 direct-administered municipalities of China, municipalities, and 2 semi-autonomous special administrative regions. Beijing is the country's capital, while Shanghai is List of cities in China by population, its most populous city by urban area and largest financial center. Considered one of six ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olmec
The Olmecs () or Olmec were an early known major Mesoamerican civilization, flourishing in the modern-day Mexican states of Veracruz and Tabasco from roughly 1200 to 400 Before the Common Era, BCE during Mesoamerica's Mesoamerican chronology, formative period. They were initially centered at the site of their development in San Lorenzo Tenochtitlán, but moved to La Venta in the 10th century BCE following the decline of San Lorenzo. The Olmecs disappeared mysteriously in the 4th century BCE, leaving the region sparsely populated until the 19th century. Among other "firsts", the Olmec appeared to practice Bloodletting in Mesoamerica, ritual bloodletting and played the Mesoamerican ballgame, hallmarks of nearly all subsequent Mesoamerican societies. The aspect of the Olmecs most familiar now is their artwork, particularly the Olmec colossal heads, colossal heads. The Olmec civilization was first defined through artifacts which collectors purchased on the pre-Columbian art mark ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New World
The term "New World" is used to describe the majority of lands of Earth's Western Hemisphere, particularly the Americas, and sometimes Oceania."America." ''The Oxford Companion to the English Language'' (). McArthur, Tom, ed., 1992. New York: Oxford University Press, p. 33: "[16c: from the feminine of ''Americus'', the Latinized first name of the explorer Amerigo Vespucci (1454–1512). The name ''America'' first appeared on a map in 1507 by the German cartographer Martin Waldseemüller, referring to the area now called Brazil]. Since the 16th century, the term "New World" has been used to describe the Western Hemisphere, often referred to as the Americas. Since the 18th century, it has come to represent the United States, which was initially colonial British America until it established independence following the American Revolutionary War. The second sense is now primary in English: ... However, the term is open to uncertainties: ..." The term arose in the early 16th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cosmetics
Cosmetics are substances that are intended for application to the body for cleansing, beautifying, promoting attractiveness, or altering appearance. They are mixtures of chemical compounds derived from either Natural product, natural sources or created synthetically. Cosmetics have various purposes, including personal care, personal and skin care. They can also be used to conceal blemishes and enhance natural features (such as the eyebrows and eyelashes). Makeup can also add colour to a person's face, enhance a person's features or change the appearance of the face entirely to resemble a different person, creature, or object. People have used cosmetics for thousands of years for skin care and appearance enhancement. Visible cosmetics for both women and men have gone in and out of fashion over the centuries. Some early forms of cosmetics contained harmful ingredients such as lead that caused serious health problems and sometimes resulted in death. Modern commercial cosmetic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rouge (cosmetics)
Rouge (; meaning "red" in French), also called blush or blusher, is a cosmetic for coloring the cheeks in a variety of shades, or the lips red. It is applied as a powder, cream or liquid. History The Ancient Egyptians were known for their creation of cosmetics, particularly their use of rouge. Ancient Egyptian pictographs show men and women wearing lip and cheek rouge. They blended fat with red ochre to create a stain that was red in color. Greek men and women eventually mimicked the look, using crushed mulberries, red beet juice, crushed strawberries, or red amaranth to create a paste. Those who wore makeup were viewed as wealthy and it symbolized status because cosmetics were costly. In China, rouge was used as early as the Shang Dynasty. It was made from the extracted juice of leaves from red and blue flowers. Some people added bovine pulp and pig pancreas to make the product denser. Women would wear the heavy rouge on their cheeks and lips. In Chinese culture, red symboliz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Near East
The Near East () is a transcontinental region around the Eastern Mediterranean encompassing the historical Fertile Crescent, the Levant, Anatolia, Egypt, Mesopotamia, and coastal areas of the Arabian Peninsula. The term was invented in the 20th century by modern Western geographers and was originally applied to the Ottoman Empire, but today has varying definitions within different academic circles. The term ''Near East'' was used in conjunction with the ''Middle East'' and the ''Far East'' (China and beyond), together known as the "three Easts"; it was a separate term from the ''Middle East'' during earlier times and official British usage. As of 2024, both terms are used interchangeably by politicians and news reporters to refer to the same region. ''Near East'' and ''Middle East'' are both Eurocentrism, Eurocentric terms. According to the National Geographic Society, the terms ''Near East'' and ''Middle East'' denote the same territories and are "generally accepted as comprisin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crystal Twinning
Crystal twinning occurs when two or more adjacent crystals of the same mineral are oriented so that they share some of the same crystal lattice points in a symmetrical manner. The result is an intergrowth of two separate crystals that are tightly bonded to each other. The surface along which the lattice points are shared in twinned crystals is called a composition surface or twin plane. Crystallographers classify twinned crystals by a number of twin laws, which are specific to the crystal structure. The type of twinning can be a diagnostic tool in mineral identification. There are three main types of twinning. The first is growth twinning which can occur both in very large and very small particles. The second is transformation twinning, where there is a change in the crystal structure. The third is deformation twinning, in which twinning develops in a crystal in response to a shear stress, and is an important mechanism for permanent shape changes in a crystal. Definition T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trigonal Crystal System
In crystallography, the hexagonal crystal family is one of the six crystal families, which includes two crystal systems (hexagonal and trigonal) and two lattice systems (hexagonal and rhombohedral). While commonly confused, the trigonal crystal system and the rhombohedral lattice system are not equivalent (see section crystal systems below). In particular, there are crystals that have trigonal symmetry but belong to the hexagonal lattice (such as α-quartz). The hexagonal crystal family consists of the 12 point groups such that at least one of their space groups has the hexagonal lattice as underlying lattice, and is the union of the hexagonal crystal system and the trigonal crystal system. There are 52 space groups associated with it, which are exactly those whose Bravais lattice is either hexagonal or rhombohedral. __TOC__ Lattice systems The hexagonal crystal family consists of two lattice systems: hexagonal and rhombohedral. Each lattice system consists of one Bravais lat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
