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Yttrialite
Yttrialite or Yttrialite-(Y) is a rare yttrium thorium sorosilicate mineral with formula: ( Y, Th)2 Si2 O7. It forms green to orange yellow masses with conchoidal fracture. It crystallizes in the monoclinic-prismatic crystal system. It has a Mohs hardness of 5 to 5.5 and a specific gravity of 4.58. It is highly radioactive due to the thorium content. It is found associated with gadolinite. It was first described in 1889 for an occurrence in the Rode Ranch pegmatite on Baringer Hill, Llano County, Texas. It has also been reported from the Suishouyama pegmatite on Honshū , historically known as , is the largest of the four main islands of Japan. It lies between the Pacific Ocean (east) and the Sea of Japan (west). It is the seventh-largest island in the world, and the second-most populous after the Indonesian ..., Japan, and from occurrences in Norway and Sweden. References Sorosilicates Yttrium minerals Thorium minerals Monoclinic minerals Minerals in space group 11< ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sorosilicates
Silicate minerals are rock-forming minerals made up of silicate groups. They are the largest and most important class of minerals and make up approximately 90 percent of Earth's crust. In mineralogy, the crystalline forms of silica (silicon dioxide, ) are usually considered to be tectosilicates, and they are classified as such in the Dana system (75.1). However, the Nickel-Strunz system classifies them as oxide minerals (4.DA). Silica is found in nature as the mineral quartz, and its polymorphs. On Earth, a wide variety of silicate minerals occur in an even wider range of combinations as a result of the processes that have been forming and re-working the crust for billions of years. These processes include partial melting, crystallization, fractionation, metamorphism, weathering, and diagenesis. Living organisms also contribute to this geologic cycle. For example, a type of plankton known as diatoms construct their exoskeletons ("frustules") from silica extracted from seawat ... [...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 mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2011): Mi ...s 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 (English: Attempt at an elementary method for the natural-historical determination and recognition of fossils); 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thorium Minerals
Thorium is a chemical element; it has symbol Th and atomic number 90. Thorium is a weakly radioactive light silver metal which tarnishes olive grey when it is exposed to air, forming thorium dioxide; it is moderately soft, malleable, and has a high melting point. Thorium is an electropositive actinide whose chemistry is dominated by the +4 oxidation state; it is quite reactive and can ignite in air when finely divided. All known thorium isotopes are unstable. The most stable isotope, 232Th, has a half-life of 14.05 billion years, or about the age of the universe; it decays very slowly via alpha decay, starting a decay chain named the thorium series that ends at stable 208 Pb. On Earth, thorium and uranium are the only elements with no stable or nearly-stable isotopes that still occur naturally in large quantities as primordial elements. Thorium is estimated to be over three times as abundant as uranium in the Earth's crust, and is chiefly refined from monazite sands as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yttrium Minerals
Yttrium is a chemical element; it has symbol Y and atomic number 39. It is a silvery-metallic transition metal chemically similar to the lanthanides and has often been classified as a "rare-earth element". Yttrium is almost always found in combination with lanthanide elements in rare-earth minerals and is never found in nature as a free element. 89Y is the only stable isotope and the only isotope found in the Earth's crust. The most important present-day use of yttrium is as a component of phosphors, especially those used in LEDs. Historically, it was once widely used in the red phosphors in television set cathode ray tube displays. Yttrium is also used in the production of electrodes, electrolytes, electronic filters, lasers, superconductors, various medical applications, and tracing various materials to enhance their properties. Yttrium has no known biological role. Exposure to yttrium compounds can cause lung disease in humans. Etymology The element is named after '' ytte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Honshū
, historically known as , is the largest of the four main islands of Japan. It lies between the Pacific Ocean (east) and the Sea of Japan (west). It is the seventh-largest island in the world, and the second-most populous after the Indonesian island of Java. Honshu had a population of 104 million , constituting 81.3% of the entire population of Japan, and mostly concentrated in the coastal areas and plains. Approximately 30% of the total population resides in the Greater Tokyo Area on the Kantō Plain. As the historical center of Japanese cultural and political power, the island includes several past Japanese capitals, including Kyōto, Nara, and Kamakura. Much of the island's southern shore forms part of the Taiheiyō Belt, a megalopolis that spans several of the Japanese islands. Honshu also contains Japan's highest mountain, Mount Fuji, and its largest lake, Lake Biwa. Most of Japan's industry is located in a belt running along Honshu's southern coast, from Tokyo to N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Llano County, Texas
Llano County () is a county located on the Edwards Plateau in the U.S. state of Texas. As of the 2020 census, its population was 21,243. Its county seat is Llano, and the county is named for the Llano River. History The Tonkawa tribe were the first known inhabitants of the region before European settlement. European settlement began by April 20, 1842, with the founding of the Adelsverein Fisher-Miller Land Grant, setting aside three million acres (12,000 km²) to settle 600 families and single men of German, Dutch, Swiss, Danish, Swedish, and Norwegian ancestry in Texas. By June 26, 1844, Henry Francis Fisher sold his interest in the land grant to the Adelsverein, and by December 20, 1845, both Fisher and Burchard Miller had sold their remaining rights to the organization. In 1847, the Meusebach–Comanche Treaty was signed, and the Bettina commune, named after German liberal Bettina Brentano von Arnim, was founded as the last Adelsverein community in Texas. Ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pegmatite
A pegmatite is an igneous rock showing a very coarse texture, with large interlocking crystals usually greater in size than and sometimes greater than . Most pegmatites are composed of quartz, feldspar, and mica, having a similar silicic composition to granite. However, rarer intermediate composition and mafic pegmatites are known. Many of the world's largest crystals are found within pegmatites. These include crystals of microcline, quartz, mica, spodumene, beryl, and tourmaline. Some individual crystals are over long. Most pegmatites are thought to form from the last fluid fraction of a large crystallizing magma body. This residual fluid is highly enriched in volatiles and trace elements, and its very low viscosity allows components to migrate rapidly to join an existing crystal rather than coming together to form new crystals. This allows a few very large crystals to form. While most pegmatites have a simple composition of minerals common in ordinary igneous rock ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gadolinite
Gadolinite, sometimes known as ytterbite, is a silicate mineral consisting principally of the silicates of cerium, lanthanum, neodymium, yttrium, beryllium, and iron with the formula . It is called gadolinite-(Ce) or gadolinite-(Y), depending on the prominent composing element (Y if yttrium predominates, and Ce if cerium). It may contain 35.5% yttria sub-group rare earths, 2.2% ceria earths, as much as to 11.6% BeO, and traces of thorium. It is found in Sweden, Norway, and the US (Texas and Colorado). Characteristics Gadolinite is fairly rare and typically occurs as well-formed crystals. It is nearly black in color and has a vitreous luster. The hardness is between 6.5 and 7 on the Mohs scale, and the specific gravity is between 4.0 and 4.7. It fractures in a conchoidal pattern and streaks grayish-green. It was also thought to exhibit pyrognomic properties, as it can emit visible light when heated to relatively low temperatures, but the scientific consensus is that this is t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specific Gravity
Relative density, also called specific gravity, is a dimensionless quantity defined as the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for solids and liquids is nearly always measured with respect to water at its densest (at ); for gases, the reference is air at room temperature (). The term "relative density" (abbreviated r.d. or RD) is preferred in SI, whereas the term "specific gravity" is gradually being abandoned. If a substance's relative density is less than 1 then it is less dense than the reference; if greater than 1 then it is denser than the reference. If the relative density is exactly 1 then the densities are equal; that is, equal volumes of the two substances have the same mass. If the reference material is water, then a substance with a relative density (or specific gravity) less than 1 will float in water. For example, an ice cube, with a relative density of about 0.91, will float. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monoclinic
In crystallography, the monoclinic crystal system is one of the seven crystal systems. A crystal system is described by three Vector (geometric), vectors. In the monoclinic system, the crystal is described by vectors of unequal lengths, as in the orthorhombic system. They form a parallelogram prism (geometry), prism. Hence two pairs of vectors are perpendicular (meet at right angles), while the third pair makes an angle other than 90°. Bravais lattices Two monoclinic Bravais lattices exist: the primitive monoclinic and the base-centered monoclinic. For the base-centered monoclinic lattice, the primitive cell has the shape of an oblique rhombic prism;See , row mC, column Primitive, where the cell parameters are given as a1 = a2, α = β it can be constructed because the two-dimensional centered rectangular base layer can also be described with primitive rhombic axes. The length a of the primitive cell below equals \frac \sqrt of the conventional cell above. Crystal class ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxygen
Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), nonmetal, and a potent oxidizing agent that readily forms oxides with most elements as well as with other chemical compound, compounds. Oxygen is abundance of elements in Earth's crust, the most abundant element in Earth's crust, making up almost half of the Earth's crust in the form of various oxides such as water, carbon dioxide, iron oxides and silicates.Atkins, P.; Jones, L.; Laverman, L. (2016).''Chemical Principles'', 7th edition. Freeman. It is abundance of chemical elements, the third-most abundant element in the universe after hydrogen and helium. At standard temperature and pressure, two oxygen atoms will chemical bond, bind covalent bond, covalently to form dioxygen, a colorless and odorless diatomic gas with the chemical formula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
