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Hexamolybdenum
Hexamolybdenum is a molybdenum dominant alloy discovered during a nanomineralogy investigation of the Allende meteorite. Hexamolybdenum was discovered in a small ultrarefractory inclusion within the Allende meteorite. This inclusion has been named ACM-1. Hexamolybdenum is hexagonal, with a calculated density of 11.90 g/cm3. The new mineral was found along with allendeite. These minerals, are believed to demonstrate conditions during the early stages of the Solar System, as is the case with many CV3 carbonaceous chondrites such as the Allende meteorite. Hexamolybdenum lies on a continuum of high-temperature alloys that are found in meteorites and allows a link between osmium, ruthenium, and iron rich meteoritic alloys. The name hexamolybdenum refers to the crystal symmetry (primitive hexagonal) and the molybdenum rich composition. The Allende meteorite fell in 1969 near Pueblito de Allende, Chihuahua, Mexico. Occurrence Hexamolybdenum was found as nano-crystals in an ultra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allendeite
Allendeite, Sc4Zr3O12, is an oxide mineral. Allendeite was discovered in a small ultrarefractory inclusion within the Allende meteorite. This inclusion has been named ACM-1. It is one of several scandium rich minerals that have been found in meteorites. Allendeite is trigonal, with a calculated density of 4.84 g/cm3. The new mineral was found along with hexamolybdenum. These minerals, are believed to demonstrate conditions during the early stages of the Solar System, as is the case with many CV3 carbonaceous chondrites such as the Allende meteorite. It is named after the Allende meteorite that fell in 1969 near Pueblito de Allende, Chihuahua, Mexico. Occurrence Allendeite was found as nano-crystals in an ultrarefractory inclusion in the Allende meteorite. The Allende meteorite has shown to be full of new minerals, after nearly forty years it has produced one in ten of the now known minerals in meteorites. This CV3 carbonaceous chondrite was the largest ever recovered ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Native Mineral
Native element minerals are those elements that occur in nature in uncombined form with a distinct mineral structure. The elemental class includes metals, intermetallic compounds, alloys, metalloids, and nonmetals. The Nickel–Strunz classification system also includes the naturally occurring phosphides, silicides, nitrides, carbides, and arsenides. Elements The following elements occur as native element minerals or alloys: Nickel–Strunz Classification -01- Native elements This list uses the Classification of Nickel–Strunz ( mindat.org, 10 ed, pending publication). ;Abbreviations: * "*" – discredited (IMA/CNMNC status). * "?" – questionable/doubtful (IMA/CNMNC status). * "REE" – Rare-earth element (Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) * "PGE" – Platinum-group element (Ru, Rh, Pd, Os, Ir, Pt) * 03.C Aluminofluorides, 06 Borates, 08 Vanadates (04.H V ,6/sup> Vanadates), 09 Silicates: ** Neso: insular (from Greek νησος nÄ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allende Meteorite
The Allende meteorite is the largest carbonaceous chondrite ever found on Earth. The fireball was witnessed at 01:05 on February 8, 1969, falling over the Mexican state of Chihuahua. After it broke up in the atmosphere, an extensive search for pieces was conducted and over 2 tonnes (2.2 tons) were recovered. The availability of large quantities of samples of the scientifically-important chondrite class has enabled numerous investigations by many scientists; it is often described as "the best-studied meteorite in history." The Allende meteorite has abundant, large calcium–aluminium-rich inclusions (CAI), which are among the oldest objects formed in the Solar System. Carbonaceous chondrites compose about 4 percent of all meteorites observed to fall from space. Prior to 1969, the carbonaceous chondrite class was known from a small number of uncommon meteorites such as Orgueil, which fell in France in 1864. Meteorites similar to Allende were known, but many were small and poorl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatemala, Belize, and the Caribbean Sea; and to the east by the Gulf of Mexico. Mexico covers ,Mexico ''''. . making it the world's 13th-largest country by are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mohs Hardness
The Mohs scale of mineral hardness () is a qualitative ordinal scale, from 1 to 10, characterizing 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 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 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 ''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 setting – ''toughness''. Minerals The Mohs scale of mineral hardness is based on the ability ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luster (mineralogy)
Lustre (British English) or luster (American English; see spelling differences) is the way light interacts with the surface of a crystal, rock, or mineral. The word traces its origins back to the Latin ''lux'', meaning "light", and generally implies radiance, gloss, or brilliance. A range of terms are used to describe lustre, such as ''earthy'', ''metallic'', ''greasy'', and ''silky''. Similarly, the term ''vitreous'' (derived from the Latin for glass, ''vitrum'') refers to a glassy lustre. A list of these terms is given below. Lustre varies over a wide continuum, and so there are no rigid boundaries between the different types of lustre. (For this reason, different sources can often describe the same mineral differently. This ambiguity is further complicated by lustre's ability to vary widely within a particular mineral species). The terms are frequently combined to describe intermediate types of lustre (for example, a "vitreous greasy" lustre). Some minerals exhibit unus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streak (mineralogy)
The streak of a mineral is the color of the powder produced when it is dragged across an un-weathered surface. Unlike the apparent color of a mineral, which for most minerals can vary considerably, the trail of finely ground powder generally has a more consistent characteristic color, and is thus an important diagnostic tool in mineral identification. If no streak seems to be made, the mineral's streak is said to be white or colorless. Streak is particularly important as a diagnostic for opaque and colored materials. It is less useful for silicate minerals, most of which have a white streak or are too hard to powder easily. The apparent color of a mineral can vary widely because of trace impurities or a disturbed macroscopic crystal structure. Small amounts of an impurity that strongly absorbs a particular wavelength can radically change the wavelengths of light that are reflected by the specimen, and thus change the apparent color. However, when the specimen is dragged to produce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Color
Color (American English) or colour (British English) is the visual perceptual property deriving from the spectrum of light interacting with the photoreceptor cells of the eyes. Color categories and physical specifications of color are associated with objects or materials based on their physical properties such as light absorption, reflection, or emission spectra. By defining a color space, colors can be identified numerically by their coordinates. Because perception of color stems from the varying spectral sensitivity of different types of cone cells in the retina to different parts of the spectrum, colors may be defined and quantified by the degree to which they stimulate these cells. These physical or physiological quantifications of color, however, do not fully explain the psychophysical perception of color appearance. Color science includes the perception of color by the eye and brain, the origin of color in materials, color theory in art, and the physics of electr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iridium
Iridium is a chemical element with the symbol Ir and atomic number 77. A very hard, brittle, silvery-white transition metal of the platinum group, it is considered the second-densest naturally occurring metal (after osmium) with a density of as defined by experimental X-ray crystallography. It is one of the most corrosion-resistant metals, even at temperatures as high as . However, corrosion-resistance is not quantifiable in absolute terms; although only certain molten salts and halogens are corrosive to solid iridium, finely divided iridium dust is much more reactive and can be flammable, whereas gold dust is not flammable but can be attacked by substances that iridium resists, such as aqua regia. Iridium was discovered in 1803 among insoluble impurities in natural platinum. Smithson Tennant, the primary discoverer, named it after the Greek goddess Iris, personification of the rainbow, because of the striking and diverse colors of its salts. Iridium is one of the rarest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bavaria
Bavaria ( ; ), officially the Free State of Bavaria (german: Freistaat Bayern, link=no ), is a state in the south-east of Germany. With an area of , Bavaria is the largest German state by land area, comprising roughly a fifth of the total land area of Germany. With over 13 million inhabitants, it is second in population only to North Rhine-Westphalia, but due to its large size its population density is below the German average. Bavaria's main cities are Munich (its capital and largest city and also the third largest city in Germany), Nuremberg, and Augsburg. The history of Bavaria includes its earliest settlement by Iron Age Celtic tribes, followed by the conquests of the Roman Empire in the 1st century BC, when the territory was incorporated into the provinces of Raetia and Noricum. It became the Duchy of Bavaria (a stem duchy) in the 6th century AD following the collapse of the Western Roman Empire. It was later incorporated into the Holy Roman Empire, became an ind ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Straubing
Straubing () is an independent city in Lower Bavaria, southern Germany. It is seat of the district of Straubing-Bogen. Annually in August the Gäubodenvolksfest, the second largest fair in Bavaria, is held. The city is located on the Danube forming the centre of the Gäuboden. History The area of Straubing has been continuously settled since the Neolithic. The conquest by the Romans in 16–14 BC had a dramatic impact on the whole region. Even today many traces of the 400-year Roman occupation can be found: for example, the famous 'Römerschatz' (Roman treasure) which was excavated in 1950 and which is shown in the Gäubodenmuseum. ''Sorviodurum'', as the Romans called it, was an important military support base. After the fall of the Roman Empire Straubing became a centre of settlement of the Bavarii, mostly around St. Peter's Church (built in the 9th century) between Allachbach and Danube. According to the customs of the Bavarii the settlement was named after their leader ''S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morocco
Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to the east, and the disputed territory of Western Sahara to the south. Mauritania lies to the south of Western Sahara. Morocco also claims the Spanish exclaves of Ceuta, Melilla and Peñón de Vélez de la Gomera, and several small Spanish-controlled islands off its coast. It spans an area of or , with a population of roughly 37 million. Its official and predominant religion is Islam, and the official languages are Arabic and Berber; the Moroccan dialect of Arabic and French are also widely spoken. Moroccan identity and culture is a mix of Arab, Berber, and European cultures. Its capital is Rabat, while its largest city is Casablanca. In a region inhabited since the Paleolithic Era over 300,000 years ago, the first Moroccan s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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