structure of diamond?
493223
http://en.wikipedia.org/wiki/Image:Diamond_unit_cell.PNG\n\nhttp://en.wikipedia.org/wiki/Diamond#Crystal_structure
863150
I believe the correct answer is two-fold. First, Carbon is a nonmetal, with very tightly bound electrons, making its intrinsic conduction of electricity rather poor, even under the most ideal of circumstances. Furthermore, semiconductor devices MUST be made of a single crystal, and in this case this would be diamond. I believe it WOULD be possible to make some transistors from diamond, but they would be prohibitively expensive to make, and thus not practical.
132243
Diamond is the hardest natural material. The Mohs hardness scale, on which diamond is a '10' and corundum (sapphire) is a '9', doesn't adequately attest to this incredible hardness, as diamond is exponentially harder than corundum. Diamond is also the least compressible and stiffest substance. It is an exceptional thermal conductor - 4 times better than copper - which gives significance to diamonds being called 'ice'. Diamond has an extremely low thermal expansion, is chemically inert with respect to most acids and alkalis, is transparent from the far infrared through the deep ultraviolet, and is one of only a few materials with a negative work function (electron affinity). One consequence of the negative electron affinity is that diamonds repel water, but readily accept hydrocarbons such as wax or grease. \n\nDiamonds do not conduct electricity well, although some are semiconductors. Diamond can burn if subjected to a high temperature in the presence of oxygen. Diamond has a high specific gravity; it is amazingly dense given the low atomic weight of carbon. The brilliance and fire of a diamond are due to its high dispersion and high refractive index. Diamond has the highest reflectance and index of refraction of any transparent substances. Diamond gemstones are commonly clear or pale blue, but colored diamonds, called 'fancies', have been found in all the colors of the rainbow. Boron, which lends a bluish color, and nitrogen, which adds a yellow cast, are common trace impurities. Two volcanic rocks that may contain diamonds are kimberlite and lamproite. Diamond crystals frequently contain inclusions of other minerals, such as garnet or chromite. Many diamonds fluoresce blue to violet, sometimes strongly enough to be seen in daylight. Some blue-fluorescing diamonds phosphoresce yellow (glow in the dark in an afterglow reaction). \n\nType of Diamonds \n\n\nNatural Diamonds \nNatural diamonds are classified by the type and quantity of impurities found within them. \n\nType Ia - This is the most common type of natural diamond, containing up to 0.3% nitrogen. \nType Ib - Very few natural diamonds are this type (~0.1%), but nearly all synthetic industrial diamonds are. Type Ib diamonds contain up to 500 ppm nitrogen. \nType IIa - This type is very rare in nature. Type IIa diamonds contain so little nitrogen that it isn't readily detected using infrared or ultraviolet absorption methods. \nType IIb - This type is also very rare in nature. Type IIb diamonds contain so little nitrogen (even lower than type IIa) that the crystal is a p-type semiconductor. \n\nSynthetic Industrial Diamonds \nSynthetic industrial diamonds are produced the process of High Pressure High Temperature Synthesis (HPHT). In HPHT synthesis, graphite and a metallic catalyst are placed in a hydraulic press under high temperatures and pressures. Over the period of a few hours the graphite converts to diamond. The resulting diamonds are usually a few millimeters in size and too flawed for use as gemstones, but they are extremely useful as edges on cutting tools and drill-bits and for being compressed to generate very high pressures. (Interesting side note: Although used to cut, grind, and polish many materials, diamonds aren't used to machine alloys of iron because the diamond abrades very quickly, due to a high-temperature reaction between iron and carbon.) \n\n\nThin Film Diamonds \nA process called Chemical Vapor Deposition (CVD) may be used to deposit thin films of polycrystalline diamond. CVD technology makes it possible to put 'zero-wear' coatings on machine parts, use diamond coatings to draw the heat away from electronic components, fashion windows that are transparent over a broad wavelength range, and take advantage of other properties of diamonds.
77745
Diamond is one of the two best known forms (or allotropes) of carbon, whose hardness and high dispersion of light makes it useful for industrial applications and jewelry (the other equally well known allotrope is graphite). Diamonds are specifically renowned as a mineral with superlative physical qualities - they make excellent abrasives because they can only be scratched by other diamonds, which also means they hold a polish extremely well and retain luster. About 130 million carats (26,000 kg) are mined annually, with a total value of nearly USD $9 billion.\n\nThe name "diamond" derives from the ancient Greek adamas (αδάμας; "impossible to tame"). They have been treasured as gems since their use as religious icons in India at least 2,500 years ago—and usage in drill bits and engraving tools also dates to early human history. Popularity of diamonds has risen since the 19th century because of improved cutting and polishing techniques, and they are commonly judged by the "four Cs": carat, clarity, color, and cut. Although nearly four times the mass of natural diamonds are produced as synthetic diamond each year, the vast majority of synthetic diamond production remains small, imperfect diamonds suitable only for industrial-grade use, with gem-quality synthetic diamonds only recently becoming available.
918762
Here is a model image of a carbon molecule:\nhttp://www.lloydminsterheavyoil.com/carbon.jpg
620932
Both diamond and graphite are network solids, in which all the atoms are covalently bonded together.\n\nThey have different types of bonding though.  This gives them different properties.\n\nGraphite consists of planes of hexagons of carbon atoms.  The bond angles in the plane are 120 degrees, and every atom is in the sp2 hybridization.  The planes are only connected together through some weaker pi-bonding between the layers, so it is relatively easy for the layers to slide past each other, making graphite soft.\n\nDiamond consists of tetrahedral bonding of carbon.  All four nearest neighbors are exactly the same distance apart.  It is in the sp3 hybridization, so the bond angles are 108.5 degrees.  All the bonds are equally strong, too.  Diamond is the hardest natural substance.  The only way to cut a diamond is to use another diamond or get it to cleave along a crystal plane (in a similar manner to cleaving graphite along the plane).\n\nThe reason for forming two different compounds is thermodynamics.  Both types of bonding are possible in carbon (sp2 and sp3 hybridization) but graphite is more stable at ambient temperature and pressure.  Diamond is more stable at high temperature and pressure.
30562
carbon is tetravalent (ie it is able to form bonds with 4 other atoms. It therefore can form backbones of more complex structures (see diamond and graphite). It is also found abundantly on earth.
794460
Diamonds are not forever\n\nPhysicists in Germany have created a material that is harder than diamond. Natalia Dubrovinskaia and colleagues at the University of Bayreuth made the new material by subjecting carbon-60 molecules to immense pressures. The new form of carbon, which is known as aggregated diamond nanorods, is expected to have many industrial applications (App. Phys. Lett. 87 083106).\n\nThe hardness of a material is measured by its isothermal bulk modulus. Aggregated diamond nanorods have a modulus of 491 gigapascals (GPa), compared with 442 GPa for conventional diamond. Dubrovinskaia and two of her co-workers - Leonid Dubrovinky and Falko Langenhorst - have patented the process used to make the new material.\n\nDiamond derives its hardness from the fact that each carbon atom is connected to four other atoms by strong covalent bonds. The new material is different in that it is made of tiny interlocking diamond rods. Each rod is a crystal that has a diameter of between 5 and 20 nanometres and a length of about 1 micron.
905772
Carbon (diamond) Silicon Germanium.\nMany more with doping and compounds\n\nhttp://en.wikipedia.org/wiki/List_of_semiconductor_materials
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The reason they are called "diamonds" is due to their shape. The name Herkimer originates from Herkimer County in New York State from which they are mined.\n\nHerkimer diamonds are quartz crystals. The crystals are fully formed on both ends & are said to be doubly terminated. Sometimes they have smaller crystals sticking out the sides.\n\nQuartz is one of the most common minerals in the earth's crust & is made up of silicon & oxygen. The chemical formula is SiO2. Diamonds are made completely from carbon. The only carbon in a Herkimer diamond is the tiny bits of black organic matter found in them. These are referred to as inclusions.\n\nI have one in my classroom. Kids hear 'diamond' & go nuts. I hear, "How much is it worth??" When I tell them not worth much they usually lose interest. LOL
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Based on this information, no, a diamond will not spontaneously decompose into graphite. It also does not imply that diamonds will last forever. It only states that diamonds are a better carbon based energy source than graphite.
64339
How about one of these on this page?\nhttp://jewelry.about.com/cs/thefourcs/tp/diamonds.htm
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Diamonds are supposed to be pure 100% carbon, but due to some impurities they are classified by their shades. \nThe shades are named as: Blue white, First Cape, Second Cape, First bye, Second bye, Off color, Light yellow , Yellow \n\n\nAlso according to their shapes when they are taken from the mine, they are classified in: \n1. Close goods \n2. Spotted stones \n3. Rejection cleavage \n4. Fine cleavage \n5. Light brown cleavage \n6. Ordinary and rejection cleavage \n7. Flats \n8. Naats \n9. Rubbish \n10. Boart\n\nFinallly each colour is sub divided according to the sizes:\nFinest extra blue white, Fine Capes \nExtra blue white, Capes \nFinest blue white, Byewaters \nBlue white, Yellows \nFinest white, Finest light brown \nWhite, Light brown \nSilver Capes, Brown and dark brown \n\nAll these colors are divided into shipments of Closed Goods, Spotteds, Irregulars, Blocks, Naats, and Flats.
93827
Diamond. It is pure carbon.
8113
because the carbon-carbon bonds in a diamond are bonded to 4 other carbon atoms in a tetrahedron pattern which is much stronger than the graphite bonds which look almost like flat sheets and have very weak atomic bonds
1186958
I know the answer. One word. DIAMONDS. lol
440980
i think its a trigonal pyramid due to the extra lone pair on the nitrogen.\n\nrefer to this site \nhttp://www.chm.bris.ac.uk/motm/ni3/ni3c.htm