Arsenic is a chemical element with the symbol As and the atomic number 33. It is a metalloid and one of the pnictogens, and therefore shares many properties with its group 15 neighbors phosphorus and antimony. Arsenic is a notoriously toxic heavy metal. It occurs naturally in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. It has various allotropes, but only the grey form, which has a metallic appearance, is important to industry.
Mineral wool is any fibrous material formed by spinning or drawing molten mineral or rock materials such as slag and ceramics.
Stibnite, sometimes called antimonite, is a sulfide mineral with the formula Sb2S3. This soft grey material crystallizes in an orthorhombic space group. It is the most important source for the metalloid antimony. The name is derived from the Greek στίβι stibi through the Latin stibium as the former name for the mineral and the element antimony.
Cadmium sulfide is the inorganic compound with the formula CdS. Cadmium sulfide is a yellow salt. It occurs in nature with two different crystal structures as the rare minerals greenockite and hawleyite, but is more prevalent as an impurity substituent in the similarly structured zinc ores sphalerite and wurtzite, which are the major economic sources of cadmium. As a compound that is easy to isolate and purify, it is the principal source of cadmium for all commercial applications. Its vivid yellow color led to its adoption as a pigment for the yellow paint "cadmium yellow" in the 1800s.
Realgar, also known as arsenic blende, ruby sulphur or ruby of arsenic, is an arsenic sulfide mineral with the chemical formula α-As4S4. It is a soft, sectile mineral occurring in monoclinic crystals, or in granular, compact, or powdery form, often in association with the related mineral, orpiment. It is orange-red in color, melts at 320 °C, and burns with a bluish flame releasing fumes of arsenic and sulfur. Realgar is soft with a Mohs hardness of 1.5 to 2 and has a specific gravity of 3.5. Its streak is orange colored. It is trimorphous with pararealgar and bonazziite.
Orpiment, also known as ″yellow arsenic blende″ is a deep-colored, orange-yellow arsenic sulfide mineral with formula As
2S
3. It is found in volcanic fumaroles, low-temperature hydrothermal veins, and hot springs and may be formed through sublimation.
Antimony trisulfide is found in nature as the crystalline mineral stibnite and the amorphous red mineral metastibnite. It is manufactured for use in safety matches, military ammunition, explosives and fireworks. It also is used in the production of ruby-colored glass and in plastics as a flame retardant. Historically the stibnite form was used as a grey pigment in paintings produced in the 16th century. In 1817, the dye and fabric chemist, John Mercer discovered the non-stoichiometric compound Antimony Orange, the first good orange pigment available for cotton fabric printing.
Chalcogenide glass is a glass containing one or more heavy chalcogens. Chalcogenide materials behave rather differently from oxides, in particular their lower band gaps contribute to very dissimilar optical and electrical properties.
Arsenic trioxide is an inorganic compound with the formula As
2O
3. As an industrial chemical, its major uses include the manufacture of wood preservatives, pesticides, and glass. It is sold under the brand name Trisenox among others when used as a medication to treat a type of cancer known as acute promyelocytic leukemia. For this use it is given by injection into a vein.
Copper monosulfide is a chemical compound of copper and sulfur. It was initially thought to occur in nature as the dark indigo blue mineral covellite. However, it was later shown to be rather a cuprous compound, formula Cu3S(S2). CuS is a moderate conductor of electricity. A black colloidal precipitate of CuS is formed when hydrogen sulfide, H2S, is bubbled through solutions of Cu(II) salts. It is one of a number of binary compounds of copper and sulfur (see copper sulfide for an overview of this subject), and has attracted interest because of its potential uses in catalysis and photovoltaics.
Arsenic pentoxide is the inorganic compound with the formula As2O5. This glassy, white, deliquescent solid is relatively unstable, consistent with the rarity of the As(V) oxidation state. More common, and far more important commercially, is arsenic(III) oxide (As2O3). All inorganic arsenic compounds are highly toxic and thus find only limited commercial applications.
Arsenic triselenide is an inorganic chemical compound with the chemical formula As2Se3.
Cadmium nitrate describes any of the related members of a family of inorganic compounds with the general formula Cd(NO3)2·xH2O. The most commonly encountered form being the tetrahydrate.The anhydrous form is volatile, but the others are colourless crystalline solids that are deliquescent, tending to absorb enough moisture from the air to form an aqueous solution. Like other cadmium compounds, cadmium nitrate is known to be carcinogenic. According to X-ray crystallography, the tetrahydrate features octahedral Cd2+ centers bound to six oxygen ligands.
Potassium arsenite (KAsO2) is an inorganic compound that exists in two forms, potassium meta-arsenite (KAsO2) and potassium ortho-arsenite (K3AsO3). It is composed of arsenite ions (AsO33− or AsO2−) with arsenic always existing in the +3 oxidation state. Like many other arsenic containing compounds, potassium arsenite is highly toxic and carcinogenic to humans. Potassium arsenite forms the basis of Fowler’s solution, which was historically used as a medicinal tonic, but due to its toxic nature its use was discontinued. Potassium arsenite is still, however, used as a rodenticide.
Gallium lanthanum sulfide glass is the name of a family of chalcogenide glasses, referred to as gallium lanthanum sulfide (Ga-La-S) glasses. They are mixtures of La2S3, La2O3, and Ga2S3, which form the basic glass with other glass modifiers added as needed. Gallium-lanthanum-sulfide glasses have a wide range of vitreous formation centered around a 70% Ga2S3 : 30% La2S3 mixture, and readily accept other modifier materials into their structure. This means that Ga-La-S composition can be adjusted to give a wide variety of optical and physical properties.
The electron-refractive effect, also known as electron induced permittivity modification (EIPM), is an electro-optic effect observed in some crystals and amorphous materials, such as chalcogenide glasses and oxides, where the permittivity reduces or increases when the material is illuminated by high energy electrons, typically from a transmission electron microscope or scanning electron microscope. The effect is non-linear and reversible.
Gallium(III) sulfide, Ga2S3, is a compound of sulfur and gallium, that is a semiconductor that has applications in electronics and photonics.
Hydrogen chalcogenides are binary compounds of hydrogen with chalcogen atoms. Water, the first chemical compound in this series, contains one oxygen atom and two hydrogen atoms, and is the most common compound on the Earth's surface.
The arsenic (As) cycle is the biogeochemical cycle of natural and anthropogenic exchanges of arsenic terms through the atmosphere, lithosphere, pedosphere, hydrosphere, and biosphere. Although arsenic is naturally abundant in the Earth's crust, long-term exposure and high concentrations of arsenic can be detrimental to human health.
Arsenic(III) telluride is an inorganic compound with the chemical formula As2Te3. It exists in two forms, the monoclinic α phase which transforms under high pressure to a rhombohedral β phase. The compound is a semiconductor, with most current carried by holes. Arsenic telluride has been examined for its use in nonlinear optics.
