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Stibnite - Herja Mine, Maramures, Romania
Stibnite, sometimes called antimonite, is a sulfide mineral, a mineral form of antimony trisulfide ( Sb2 S3). It is a soft, metallic grey crystalline solid with an orthorhombic space group. It is the most important source for the metalloid antimony. The name is derived from the Greek through the Latin as the former name for the mineral and the element antimony. Structure Stibnite has a structure similar to that of arsenic trisulfide, As2S3. The Sb(III) centers, which are pyramidal and three-coordinate, are linked via bent two-coordinate sulfide ions. However, some studies suggest that the actual coordination polyhedra of antimony are SbS7, with (3+4) coordination at the M1 site and (5+2) at the M2 site. Some of the secondary bonds impart cohesion and are connected with packing. Stibnite is grey when fresh, but can turn superficially black due to oxidation in air. Properties The melting point of Sb2S3 is . The band gap is 1.88 eV at room temperature and it is a phot ... [...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] |
Eye Liner
An eye is a sensory organ that allows an organism to perceive visual perception, visual information. It detects light and converts it into electro-chemical impulses in neurons (neurones). It is part of an organism's visual system. In higher organisms, the eye is a complex optics, optical system that collects light from the surrounding environment, regulates its intensity through a Iris (anatomy), diaphragm, Focus (optics), focuses it through an adjustable assembly of Lens (anatomy), lenses to form an image, converts this image into a set of electrical signals, and transmits these signals to the brain through neural pathways that connect the eye via the optic nerve to the visual cortex and other areas of the brain. Eyes with resolving power have come in ten fundamentally different forms, classified into compound eyes and non-compound eyes. Compound eyes are made up of multiple small visual units, and are common on insects and crustaceans. Non-compound eyes have a single lens a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philosopher's Stone
The philosopher's stone is a mythic alchemical substance capable of turning base metals such as mercury into gold or silver; it was also known as "the tincture" and "the powder". Alchemists additionally believed that it could be used to make an elixir of life which made possible rejuvenation and immortality. For many centuries, it was the most sought-after goal in alchemy. The philosopher's stone was the central symbol of the mystical terminology of alchemy, symbolizing perfection at its finest, divine illumination, and heavenly bliss. Efforts to discover the philosopher's stone were known as the Magnum Opus ("Great Work"). Antiquity The earliest known written mention of the philosopher's stone is in the ''Cheirokmeta'' by Zosimos of Panopolis (). Alchemical writers assign a longer history. Elias Ashmole and the anonymous author of ''Gloria Mundi'' (1620) claim that its history goes back to Adam, who acquired the knowledge of the stone directly from God. This knowledge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George Starkey (alchemist)
George Starkey (1628–1665) was a Colonial American alchemist, medical practitioner, and writer of numerous commentaries and chemical treatises that were widely circulated in Western Europe and influenced prominent men of science, including Robert Boyle and Isaac Newton. After relocating from New England to London, England, in 1650, Starkey began writing under the pseudonym Eirenaeus Philalethes. Starkey remained in England and continued his career in medicine and alchemy until his death in the Great Plague of London in 1665. Early life Starkey was born in Bermuda, the first of at least five children of George Stirk, a Scottish minister and devoted Calvinist, and Elizabeth Painter. During his early years in Bermuda, Starkey displayed interest in natural history, as evidenced by his written entomological observations of various insects indigenous to Bermuda. After the death of his father in 1637, Starkey was sent to New England, where he continued his early education before enroll ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Collyrium
In eye care, collyrium is an antique term for a lotion or liquid wash used as a cleanser for the eyes, particularly in diseases of the eye. The word ''collyrium'' comes from the Greek , eye-salve. The same name was also given to unguents used for the same purpose, such as unguent of tutty (Sanskrit ''tuttha'' meaning variously zinc oxide or blue vitriol). Lastly, the name was given, though improperly, to some liquid medicines used against venereal diseases. Pre-modern medicine distinguished two kinds of collyriums: the one liquid, the other dry. Liquid collyriums were composed of ophthalmic powders, or waters, such as rose-water, plantain-water, that of fennel, eyebright, etc., in which was dissolved tutty, white vitriol, or some other proper powder. Dry collyriums were pastilles of Rhasis, sugar-candy, iris, tutty prepared and blown into the eye with a little pipe. The 2nd century Mishnah mentioncollyrium The Sunan Abu Dawood reports, "Prophet Muhammad said: 'Among th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sunan Abi Dawood
''Sunan Abi Dawud'' () is the third hadith collection of the Six Books of Sunni Islam. It was compiled by scholar Abu Dawud al-Sijistani (). Introduction Abu Dawood compiled twenty-one books related to Hadith and preferred those (plural of "Hadith") which were supported by the example of the companions of Muhammad. As for the contradictory , he states under the heading of 'Meat acquired by hunting for a pilgrim': "if there are two contradictory reports from the Prophet (SAW), an investigation should be made to establish what his companions have adopted". He wrote in his letter to the people of Mecca: "I have disclosed wherever there was too much weakness in regard to any tradition in my collection. But if I happen to leave a Hadith without any comment, it should be considered as sound, albeit some of them are more authentic than others". The Mursal Hadith (a tradition in which a companion is omitted and a successor narrates directly from Muhammad) has also been a matter of d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancient Egypt
Ancient Egypt () was a cradle of civilization concentrated along the lower reaches of the Nile River in Northeast Africa. It emerged from prehistoric Egypt around 3150BC (according to conventional Egyptian chronology), when Upper and Lower Egypt were amalgamated by Menes, who is believed by the majority of List of Egyptologists, Egyptologists to have been the same person as Narmer. The history of ancient Egypt unfolded as a series of stable kingdoms interspersed by the "Periodization of ancient Egypt, Intermediate Periods" of relative instability. These stable kingdoms existed in one of three periods: the Old Kingdom of Egypt, Old Kingdom of the Early Bronze Age; the Middle Kingdom of Egypt, Middle Kingdom of the Middle Bronze Age; or the New Kingdom of Egypt, New Kingdom of the Late Bronze Age. The pinnacle of ancient Egyptian power was achieved during the New Kingdom, which extended its rule to much of Nubia and a considerable portion of the Levant. After this period, Egypt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Static Electricity
Static electricity is an imbalance of electric charges within or on the surface of a material. The charge remains until it can move away by an electric current or electrical discharge. The word "static" is used to differentiate it from electric current, current electricity, where an electric charge flows through an electrical conductor. A static electric charge can be created whenever two surfaces contact and/or slide against each other and then separate. The effects of static electricity are familiar to most people because they can feel, hear, and even see sparks if the excess charge is neutralized when brought close to an electrical conductor (for example, a path to ground), or a region with an excess charge of the opposite polarity (positive or negative). The familiar phenomenon of a static shockmore specifically, an electrostatic dischargeis caused by the neutralization of a charge. Causes Materials are made of atoms that are normally electrically neutral because they contai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flash (photography)
A flash is a device used in photography that produces a brief burst of light (lasting around of a second) at a color temperature of about 5500 K to help illuminate a scene. The main purpose of a flash is to illuminate a dark scene. Other uses are capturing quickly moving objects or changing the quality of light. ''Flash'' refers either to the flash of light itself or to the electronic flash unit discharging the light. Most current flash units are electronic, having evolved from single-use flashbulbs and flammable powders. Modern cameras often activate flash units automatically. Flash units are commonly built directly into a camera. Some cameras allow separate flash units to be mounted via a standardized accessory mount bracket (a '' hot shoe''). In professional studio equipment, flashes may be large, standalone units, or studio strobes, powered by special battery packs or connected to mains power. They are either synchronized with the camera using a flash synchronization ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Safety Match
A match is a tool for starting a fire. Typically, matches are made of small wooden sticks or stiff paper. One end is coated with a material that can be ignited by friction generated by striking the match against a suitable surface. Wooden matches are packaged in matchboxes, and paper matches are partially cut into rows and stapled into matchbooks. The coated end of a match, known as the match "head", consists of a bead of active ingredients and binder, often colored for easier inspection. There are two main types of matches: safety matches, which can be struck only against a specially prepared surface, and strike-anywhere matches, for which any suitably frictional surface can be used. Etymology The word ''match'' derives from Old French ''mèche'', referring to the wick of a candle. Historically, the term ''match'' referred to lengths of cord (later cambric) impregnated with chemicals, and allowed to burn continuously. These were used to light fires and fire guns (see matchl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flash Powder
Flash powder is a pyrotechnic composition, a mixture of an oxidizer and a metallic fuel, which burns quickly (deflagrates) and produces a loud noise, regardless of confinement in some formulations. It is widely used in theatrical and display pyrotechnics and consumer fireworks (namely firecrackers, professional salutes, and formerly in banned items such as cherry bombs and M-80s) and was once used for flashes in photography. Different varieties of flash powder are made from different compositions; most common are potassium perchlorate and aluminium powder. Early formulations used potassium chlorate instead of potassium perchlorate. Flash powder compositions are also used in military pyrotechnics when production of large amount of noise or light is required, e.g., stun grenades, battle simulator devices, and photoflash bombs. History Lycopodium powder is a yellow-tan dust-like powder historically used as a flash powder. Today, the principal use of the powder is to create ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrotechnic Star
Pyrotechnic stars are pellets of pyrotechnic composition which may contain metal powders, salts or other compounds that, when ignited, burn a certain color or make a certain spark effect. They are a part of all projectile-type fireworks. The most common is the aerial shell. When watching this firework, it will launch into the sky, burning a lifting charge. Once the shell has attained proper altitude, due to other mechanisms within the firework, it will ignite the stars. Procedure Stars are either rolled, pumped or cut. *Rolled stars are small cores of a hard material (often lead shot or an organic material such as mustard seeds or even cut stars) which are coated in a rotating mixer similar to a concrete mixer. First, water is sprayed on these cores. Then an amount of a pyrotechnic composition is placed into the mixer. As these two steps are repeated, the stars grow into a larger spherical shape. *Pumped stars are stars that have been pumped using a star pump. A dampened comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
