"dispersion of light of diamond make it useful for both industrial applications and jewelry. Diamond is the hardest known natural mineral. This makes it an excellent abrasive and makes it hold polish and luster extremely well. No known naturally occurring substance can cut (or even scratch) a diamond, except another diamond. The market for industrial-grade diamonds operates much differently from its gem-grade counterpart. Industrial diamonds are valued mostly for their hardness and heat conductivity, making many of the gemological characteristics of diamond, including clarity and color, mostly irrelevant. This helps explain why 80% of mined diamonds (equal to about 100"
"(""proper"", ""unalterable"", ""unbreakable"") and sometimes called adamant, diamond is the hardest known naturally occurring material, scoring 10 on the Mohs scale of mineral hardness. Diamond is extremely strong owing to the structure of its carbon atoms, where each carbon atom has four neighbors joined to it with covalent bonds. The material boron nitride, when in a form structurally identical to diamond (zincblende structure), is nearly as hard as diamond; a currently hypothetical material, beta carbon nitride, may also be as hard or harder in one form. It has been shown that some diamond aggregates having nanometer grain size are harder"
"the softest known substances, and diamond, the hardest naturally occurring substance. It bonds readily with other small atoms, including other carbon atoms, and is capable of forming multiple stable covalent bonds with suitable multivalent atoms. Carbon is known to form almost ten million different compounds, a large majority of all chemical compounds. Carbon also has the highest sublimation point of all elements. At atmospheric pressure it has no melting point, as its triple point is at and , so it sublimes at about 3,900 K. Graphite is much more reactive than diamond at standard conditions, despite being more thermodynamically stable,"
"aggregated diamond nanorods, which is harder than bulk diamond and is currently the hardest (~150 GPa) material known. Superhard material A superhard material is a material with a hardness value exceeding 40 gigapascals (GPa) when measured by the Vickers hardness test. They are highly incompressible solids with high electron density and high bond covalency. As a result of their unique properties, these materials are of great interest in many industrial areas including, but not limited to, abrasives, polishing and cutting tools and wear-resistant and protective coatings. Diamond is the hardest known material to date, with a Vickers hardness in the"
"Superhard material A superhard material is a material with a hardness value exceeding 40 gigapascals (GPa) when measured by the Vickers hardness test. They are highly incompressible solids with high electron density and high bond covalency. As a result of their unique properties, these materials are of great interest in many industrial areas including, but not limited to, abrasives, polishing and cutting tools and wear-resistant and protective coatings. Diamond is the hardest known material to date, with a Vickers hardness in the range of 70–150 GPa. Diamond demonstrates both high thermal conductivity and electrically insulating properties and much attention has"
"""nanocrystalline"" and ""microcrystalline"" diamond, respectively. Synthetic diamond is the hardest known material, where hardness is defined as resistance to indentation. The hardness of synthetic diamond depends on its purity, crystalline perfection and orientation: hardness is higher for flawless, pure crystals oriented to the <nowiki>[</nowiki>111<nowiki>]</nowiki> direction (along the longest diagonal of the cubic diamond lattice). Nanocrystalline diamond produced through CVD diamond growth can have a hardness ranging from 30% to 75% of that of single crystal diamond, and the hardness can be controlled for specific applications. Some synthetic single-crystal diamonds and HPHT nanocrystalline diamonds (see hyperdiamond) are harder than any known"
"Boron carbide Boron carbide (chemical formula approximately BC) is an extremely hard boron–carbon ceramic, and covalent material used in tank armor, bulletproof vests, engine sabotage powders, as well as numerous industrial applications. With a Vickers Hardness of >30 GPa, it is one of the hardest known materials, behind cubic boron nitride and diamond. Boron carbide was discovered in 19th century as a by-product of reactions involving metal borides, but its chemical formula was unknown. It was not until the 1930s that the chemical composition was estimated as BC. There remained, however, controversy as to whether or not the material had"
"and carbon atoms on the different positions in the crystal determines several of the materials properties - in particular, the crystal symmetry of the BC composition and the non-metallic electrical character of the BC composition. Boron carbide is known as a robust material having high hardness, high cross section for absorption of neutrons (i.e. good shielding properties against neutrons), stability to ionizing radiation and most chemicals. Its Vickers hardness (38 GPa), Elastic Modulus (460 GPa) and fracture toughness (3.5 MPa·m) approach the corresponding values for diamond (1150 GPa and 5.3 MPa·m). , boron carbide is the third hardest substance known,"
"Material properties of diamond Diamond is the allotrope of carbon in which the carbon atoms are arranged in the specific type of cubic lattice called diamond cubic. Diamond is an optically isotropic crystal that is transparent to opaque. Diamond is the hardest naturally occurring material known. Yet, due to important structural weaknesses, diamond's toughness is only fair to good. The precise tensile strength of diamond is unknown, however strength up to 60 GPa has been observed, and it could be as high as 90–225 GPa depending on the crystal orientation. The anisotropy of diamond hardness is carefully considered during diamond"
"Carbonado Carbonado, commonly known as the ""black diamond"", is the toughest form of natural diamond. It is an impure form of polycrystalline diamond consisting of diamond, graphite, and amorphous carbon. It is found primarily in alluvial deposits in the Central African Republic and in Brazil. Its natural colour is black or dark grey, and it is more porous than other diamonds. Carbonado diamonds are typically pea-sized or larger porous aggregates of many tiny black crystals. The most characteristic carbonados have been found only in the Central African Republic and in Brazil, in neither place associated with kimberlite, the source of"
"the current heaviest element known, oganesson. In 1787, Swedish part-time chemist Carl Axel Arrhenius found a heavy black rock near the Swedish village of Ytterby, Sweden (part of the Stockholm Archipelago). Thinking that it was an unknown mineral containing the newly discovered element tungsten, he named it ytterbite. Finnish scientist Johan Gadolin identified a new oxide or ""earth"" in Arrhenius' sample in 1789, and published his completed analysis in 1794; in 1797, the new oxide was named ""yttria"". In the decades after French scientist Antoine Lavoisier developed the first modern definition of chemical elements, it was believed that earths could"
"Toxic heavy metal A toxic heavy metal is any relatively dense metal or metalloid that is noted for its potential toxicity, especially in environmental contexts. The term has particular application to cadmium, mercury, lead and arsenic, all of which appear in the World Health Organization's list of 10 chemicals of major public concern. Other examples include manganese, chromium, cobalt, nickel, copper, zinc, selenium, silver, antimony and thallium. Heavy metals are found naturally in the earth. They become concentrated as a result of human caused activities and can enter plant, animal, and human tissues via inhalation, diet, and manual handling. Then,"
"a streak on paper (hence its name, from the Greek verb ""γράφειν"" which means ""to write""), while diamond is the hardest naturally occurring material known. Graphite is a good electrical conductor while diamond has a low electrical conductivity. Under normal conditions, diamond, carbon nanotubes, and graphene have the highest thermal conductivities of all known materials. All carbon allotropes are solids under normal conditions, with graphite being the most thermodynamically stable form at standard temperature and pressure. They are chemically resistant and require high temperature to react even with oxygen. The most common oxidation state of carbon in inorganic compounds is"
"or minimize shock and vibration. Regularly spaced, the protruding air-filled hemispheres are known as ""bubbles"" which are 1/4 inch (6 millimeters) in diameter, to as large as an inch (26 millimeters) or more. Air-bubble packing was co-invented by Alfred Fielding and Marc Chavannes in 1957. 1957 Borazon Borazon, a boron nitride allotrope, is the fourth hardest substance, after aggregated diamond nanorods, ultrahard fullerite, and diamond, and the third hardest artificial material. Borazon is a crystal created by heating equal quantities of boron and nitrogen at temperatures greater than 1800 °Celsius, 3300 °Fahrenheit at 7 gigapascal 1 millionpound-force per square inch."
"Natural isotopes Natural isotopes are either stable isotopes, radioactive isotopes that have a sufficiently long half-life to allow them to exist in substantial concentrations in the Earth (e.g. bismuth-209, with a half-life of 1.9 * 10 years, potassium-40 with a half-life of 1.251(3)×10 y), daughter products of those isotopes (e.g. Th, with a half-life of 24 days) or cosmogenic elements. The heaviest stable isotope is lead-208, but the heaviest 'natural' isotope is U-238. Many elements have both natural and artificial isotopes (e.g. hydrogen has three natural isotopes and another four known artificial isotopes). A further distinction among stable natural isotopes"
"necessarily constant for all sides, which is a function of its structure; crystallographic weakness renders some directions softer than others. An example of this property exists in kyanite, which has a Mohs hardness of 5½ parallel to [001] but 7 parallel to [100]. The most common scale of measurement is the ordinal Mohs hardness scale. Defined by ten indicators, a mineral with a higher index scratches those below it. The scale ranges from talc, a phyllosilicate, to diamond, a carbon polymorph that is the hardest natural material. The scale is provided below: Lustre indicates how light reflects from the mineral's"
"Hardness Hardness is a measure of the resistance to localized plastic deformation induced by either mechanical indentation or abrasion. Some materials (e.g. metals) are harder than others (e.g. plastics, wood). Macroscopic hardness is generally characterized by strong intermolecular bonds, but the behavior of solid materials under force is complex; therefore, there are different measurements of hardness: ""scratch hardness"", ""indentation hardness"", and ""rebound hardness"". Hardness is dependent on ductility, elastic stiffness, plasticity, strain, strength, toughness, viscoelasticity, and viscosity. Common examples of hard matter are ceramics, concrete, certain metals, and superhard materials, which can be contrasted with soft matter. There are three"
"This carbyne is of considerable interest to nanotechnology as its Young's modulus is 40 times that of the hardest known material – diamond. In 2015, a team at the North Carolina State University announced the development of another allotrope they have dubbed Q-carbon, created by a high energy low duration laser pulse on amorphous carbon dust. Q-carbon is reported to exhibit ferromagetism, fluorescence, and a hardness superior to diamonds. Carbon is the fourth most abundant chemical element in the observable universe by mass after hydrogen, helium, and oxygen. Carbon is abundant in the Sun, stars, comets, and in the atmospheres"
"Osmium Osmium (from Greek ὀσμή ""osme"", ""smell"") is a chemical element with symbol Os and atomic number 76. It is a hard, brittle, bluish-white transition metal in the platinum group that is found as a trace element in alloys, mostly in platinum ores. Osmium is the densest naturally occurring element, with an experimentally measured (using x-ray crystallography) density of . Manufacturers use its alloys with platinum, iridium, and other platinum-group metals to make fountain pen nib tipping, electrical contacts, and in other applications that require extreme durability and hardness. The element's abundance in the Earth's crust is among the rarest."
"to a very large kinetic energy barrier, diamonds are metastable; they will not decay into graphite under normal conditions. Material properties of diamond Diamond is the allotrope of carbon in which the carbon atoms are arranged in the specific type of cubic lattice called diamond cubic. Diamond is an optically isotropic crystal that is transparent to opaque. Diamond is the hardest naturally occurring material known. Yet, due to important structural weaknesses, diamond's toughness is only fair to good. The precise tensile strength of diamond is unknown, however strength up to 60 GPa has been observed, and it could be as"
"the melting point of BC and is accompanied by liberation of large amount of carbon monoxide: If magnesium is used, the reaction can be carried out in a graphite crucible, and the magnesium byproducts are removed by treatment with acid. Boron carbide Boron carbide (chemical formula approximately BC) is an extremely hard boron–carbon ceramic, and covalent material used in tank armor, bulletproof vests, engine sabotage powders, as well as numerous industrial applications. With a Vickers Hardness of >30 GPa, it is one of the hardest known materials, behind cubic boron nitride and diamond. Boron carbide was discovered in 19th century"
"February 2010. The heaviest element that is believed to have been synthesized to date is element 118, oganesson, on 9 October 2006, by the Flerov Laboratory of Nuclear Reactions in Dubna, Russia. Tennessine, element 117 was the latest element claimed to be discovered, in 2009. On 28 November 2016, scientists at the IUPAC officially recognized the names for four of the newest chemical elements, with atomic numbers 113, 115, 117, and 118. The following sortable table shows the 118 known chemical elements. Chemical element A chemical element is a species of atoms having the same number of protons in their"
"been suggested as to its use in nature, with the most popular being to automatically tension webs built in the night using the morning dew. The toughest known spider silk is produced by the species Darwin's bark spider (""Caerostris darwini""): ""The toughness of forcibly silked fibers averages 350 MJ/m, with some samples reaching 520 MJ/m. Thus, ""C. darwini"" silk is more than twice as tough as any previously described silk, and over 10 times tougher than Kevlar"". Silk fibre is a two-compound pyriform secretion, spun into patterns (called ""attachment discs"") that are employed to adhere silk threads to various surfaces"
"darwini"" was found. Six more species, four of these from Madagascar, were described in 2015. A molecular phylogenetic study of 12 of the species of ""Caerostris"", including ""C. darwini"", produced the phylogenetic tree shown below. The spider's silk is the toughest biological material ever studied, over ten times tougher than a similarly-sized piece of Kevlar. The average toughness of the fibres is 350 MJ/m, and some are up to 520 MJ/m, making the silk twice as tough as any other spider silk known. The web of Darwin's bark spider is remarkable in that it is not only the longest spanning"
"in the US, made possible by the development of new apparatus and techniques, became a milestone in synthesis of artificial superhard materials. The synthesis clearly showed the potential of high-pressure applications for industrial purposes and stimulated growing interest in the field. Four years after the first synthesis of artificial diamond, cubic boron nitride c-BN was obtained and found to be the second hardest solid. Synthetic diamond can exist as a single, continuous crystal or as small polycrystals interconnected through the grain boundaries. The inherent spatial separation of these subunits causes the formation of grains, which are visible by the unaided"
"Tennessine Tennessine is a synthetic chemical element with symbol Ts and atomic number 117. It is the second-heaviest known element and the penultimate element of the 7th period of the periodic table. The discovery of tennessine was officially announced in Dubna, Russia, by a Russian–American collaboration in April 2010, which makes it the most recently discovered element . One of its daughter isotopes was created directly in 2011, partially confirming the results of the experiment. The experiment itself was repeated successfully by the same collaboration in 2012 and by a joint German–American team in May 2014. In December 2015, the"
"Vanadium carbide Vanadium carbide is the inorganic compound with the formula VC. It is an extremely hard refractory ceramic material. With a hardness of 9-9.5 Mohs, it is possibly the hardest metal-carbide known. It is of interest because it is prevalent in vanadium metal and alloys. Being isomorphous with vanadium monoxide, it crystallizes in the rock salt structure. Because VC and VO are miscible, samples of VC typically contain an impurity of the oxide. It is produced by heating vanadium oxides with carbon at around 1000 °C. Vanadium carbide can be formed in the (111) orientation, when formed by radio"
"Tungsten hexafluoride Tungsten(VI) fluoride, also known as tungsten hexafluoride, is an inorganic compound with the formula WF. It is a toxic, corrosive, colorless gas, with a density of about 13 g/L (roughly 11 times heavier than air.) It is one of the heaviest known gases under standard conditions. WF is commonly used by the semiconductor industry to form tungsten films, through the process of chemical vapor deposition. This layer serves as a low-resistivity metallic ""interconnect"". It is one of seventeen known binary hexafluorides. The WF molecule is octahedral with the symmetry point group of O. The W–F bond distances are"
"crystal. Solid carbon comes in different forms known as allotropes depending on the type of chemical bond. The two most common allotropes of pure carbon are diamond and graphite. In graphite the bonds are sp orbital hybrids and the atoms form in planes with each bound to three nearest neighbors 120 degrees apart. In diamond they are sp and the atoms form tetrahedra with each bound to four nearest neighbors. Tetrahedra are rigid, the bonds are strong, and of all known substances diamond has the greatest number of atoms per unit volume, which is why it is both the hardest"
"can be violent, similar to the addition of water to sulfuric acid but much more violent. Fluorosulfuric acid Fluorosulfuric acid (IUPAC name: sulfurofluoridic acid) is the inorganic compound with the chemical formula HSOF. It is one of the strongest acids commercially available. The formula HSOF emphasizes its relationship to sulfuric acid, HSO; HSOF is a tetrahedral molecule. It is a colourless liquid, although commercial samples are often yellow. Fluorosulfuric acid is a free-flowing colorless liquid. It is soluble in polar organic solvents (e.g. nitrobenzene, acetic acid, and ethyl acetate), but poorly soluble in nonpolar solvents such as alkanes. Reflecting its"
"all the time because of cosmic radiation. For carbon-14 this fact has practice value because it is used for radiocarbon dating. Natural isotopes Natural isotopes are either stable isotopes, radioactive isotopes that have a sufficiently long half-life to allow them to exist in substantial concentrations in the Earth (e.g. bismuth-209, with a half-life of 1.9 * 10 years, potassium-40 with a half-life of 1.251(3)×10 y), daughter products of those isotopes (e.g. Th, with a half-life of 24 days) or cosmogenic elements. The heaviest stable isotope is lead-208, but the heaviest 'natural' isotope is U-238. Many elements have both natural and"
"limited investigation of dubnium chemistry has confirmed this. Solution chemistry experiments have revealed that dubnium often behaves more like niobium rather than tantalum, breaking periodic trends. Uranium, element 92, is the heaviest element to occur in significant quantity in nature; heavier elements can only be produced practically by synthesis. The first synthesis of a new element—neptunium, element 93—was achieved in 1940 by a team of researchers in the United States. In the following years, American scientists synthesized the elements up to mendelevium, element 101, which was synthesized in 1955. From element 102, the priority of discoveries was contested between American"
"Topaz Topaz is a silicate mineral of aluminium and fluorine with the chemical formula AlSiO(F, OH). Topaz crystallizes in the orthorhombic system, and its crystals are mostly prismatic terminated by pyramidal and other faces. It is one of the hardest naturally occurring minerals (Mohs hardness of 8) and is the hardest of any silicate mineral. This hardness combined with its usual transparency and variety of colors means that it has acquired wide use in jewellery as a cut gemstone as well as for intaglios and other gemstone carvings. Topaz in its natural state is a golden brown to yellow, a"