I heard that either, cubic zirconium, or diamond, has that same phase velocity of water?
815534
Diamonds placed in water appear to disappear (other than any flaws in them).  When they are removed from water, they are not wet.
330145
Solid and in solids Diamond.\n\nSecond  Alummina and titanium carbide.
592262
sodium chloride definately or cesium fluoride (not sure)-evaporation of water solution\n\npresume you mean cubic close packing
804135
diamonds are made of carbon.\nA diamond is a transparent crystal of tetrahedrally bonded carbon atoms. Diamonds have been adapted for many uses because of the material's exceptional physical characteristics. Most notable are its extreme hardness of diamond, its high dispersion index, and high thermal conductivity.\n\nThere form under extreme heat and pressure.\nDiamonds are formed by prolonged exposure of carbon bearing materials to high pressure and temperature. On Earth, the formation of diamonds is possible because there are regions deep within the Earth that are at a high enough pressure and temperature that the formation of diamonds is thermodynamically favorable. Under continental crust, diamonds form starting at depths of about 150 kilometers (90 miles), where pressure is roughly 5 gigapascals and the temperature is around 1200 degrees Celsius (2200 degrees Fahrenheit).\n\nWhere are they found?\nHistorically diamonds were known to be found only in alluvial deposits in southern India; India led the world in diamond production from the time of their discovery in approximately the 9th century BCE to the mid-18th century CE, but the commercial potential of these sources has been exhausted. The first non-Indian diamond source was found in Brazil in 1725. While no commercial diamond production exists in the US, Arkansas is the only state to have a verifiable source of diamonds. Today, most commercially viable diamond deposits are in Africa, notably in South Africa, Namibia, Botswana, the Democratic Republic of Congo, Angola, Tanzania and Sierra Leone [5]. There are also commercial deposits being actively mined in the Northwest Territories of Canada, Siberia (mostly in Yakutia territory, for example Mir pipe and Udachnaya pipe), Brazil, and in Northern and Western Australia. Diamond prospectors continue to search the globe for diamond-bearing kimberlite and lamproite pipes.\n\nWhat are they used for?\nThe dominant industrial use of diamond is in cutting, drilling, grinding, and polishing. Most uses of diamonds in these technologies do not require large diamonds; in fact, most diamonds that are gem-quality except for their small size, can find an industrial use. Diamonds are embedded in drill tips or saw blades, or ground into a powder for use in grinding and polishing applications. Specialized applications include use in laboratories as containment for high pressure experiments (see diamond anvil), high-performance bearings, and limited use in specialized windows.
15296
Here is the exact answer you need:\n\nOn the basis of their macroscopic properties, it seems impropable that diamonds and graphite are made of exactly the same atoms. This begs the question, how do we know that diamonds are indeed carbon? Surprisingly, this has been known for over 200 years. In 1772 (before the signing of the Declaration of Independence) a talented French chemist, Antoine Lavoisier, burned diamond (ca. 150 milligrams) in a sealed container. Diamonds do not burn readily, so Lavoisier used the high heat provided by a large lens placed in the sunlight. By a simple analysis of the gases produced by burning, Lavoisier determined that the gas we now know as CO2 was produced. Furthermore, the same amount of this gas was produced when 150 milligrams of amorphous carbon in the form of charcoal was burned. Thus, Lavoisier concluded that charcoal and diamond are the same. However Lavoisier was reluctant to publicize such a radical and counterintuitive result. It took more than 20 years before Lavoisier's conclusions were confirmed by Tenant, an English chemist. Let us examine Lavoisier's conclusion in the context of the times. Lavoisier's discovery predated Dalton's formulation that all matter is made of elements by 29 years and Mendeleev's formulation of the periodic table by almost 100 years. Our modern understanding of chemistry allows us to formulate Lavoisier's experiments in a compact way, the chemical equation.\n\n\n\n\n\nThese equations indicate that burning either diamond or graphite causes the bonds of the reactants (the carbon material and dioxygen) to be rearranged to form the product (CO2) and energy in the form of heat. In general, a chemical reaction involves changes in the bonding between atoms in going from reactants to products. Let's contrast these combustion equations with the analogous equation for burning buckyballs.\n\n\n\nNote how the buckyball equation has a subscript of 60 on the carbon, indicating that this form of carbon is molecular. As a result, 60 dioxygen molecules are required to convert the sixty atoms of carbon in each buckyball into 60 molecules of CO2. In a proper, balanced chemical equation the number and types of atoms on the reactant (left) side of the equation equal those on the product (right) side. Because heat is released in this chemical reaction, heat is written as a product. Reactions that generate heat are called exothermic.\n\n\nHope this is enough.
857221
No. The equilibrium constant is thermodynamic. Reaction rate is kinetic. The conversion of diamond to graphite at 1 atmosphere has a high equilibrium constant. Do you see diamonds turning rapidly to graphite?
775695
Diamonds can scratch glass...I don't believe zirconium has the same property.  You can tell with pearls if you rub them against your teeth...real ones are gritty feeling, fake ones are smooth.\n\nAs for the others, I think it requires a gemologist or someone well versed in dealing with gems.
97864
yes, with an alloy or equal or lower melting point
1108940
Well, it doesn't, really, except that since the law of definite composition says that substances always have the same ratio of the same atoms, they're going to have the same properties, including density (mass per unit volume).  Water is always two hydrogen atoms to one oxygen atom, and will always have a density of 1.00 grams per milliliter at 4 degrees Celsius.  Same applies to all other substances.  In terms of it relating directly to volume, though, it doesn't.
792378
Cubic zirconia is so optically close to diamond that only a trained eye can easily differentiate the two. There are a few key features of CZ which distinguish it from diamond, some observable only under the microscope or loupe. For example:\n\nDispersion. With a dispersive power greater than diamond (0.060 vs. 0.044) the more prismatic fire of CZ can be seen by even an untrained eye. \nHardness. CZ has an 8.5 to 9.0 on the Mohs' hardness scale vs. a rating of 10 for diamonds. \nSpecific gravity. CZs are heavyweights in comparison to diamonds; a CZ will weigh about 1.7 times more than a diamond of equivalent size. Obviously, this difference is only useful when examining loose stones. \nFlaws. Contemporary production of cubic zirconia is virtually flawless, whereas most diamonds have some sort of defect, be it a feather, included crystal, or perhaps a remnant of an original crystal face (e.g. trigons). \nRefractive index. CZ has a refractive index of 2.176, compared to a diamond's 2.417. \nCut. Under close inspection with a loupe, the facet shapes of some CZs appear different from diamonds. \nIn theory, many gems (such as CZs and diamonds) look best when the star facet, crown main facets, and upper girdle facets do not quite meet. (Per Step 11 of editor's note 36 to Marcel Tolkowsky's Diamond Design.) Diamond has such a high refractive index that having these facets meet at a single point does not cause much loss of fire or reflection. Diamonds normally have these facets meet at a point, because that is more symmetrical and reflects well on the cutter's precision. On the other hand, CZ has a considerably lower refractive index than diamond. CZs are often cut with 6-sided crown main facets, so that the star facets do not touch the upper girdle facets. This optimizes the brilliance and fire of the CZs. \nThe optimum angle of the main crown facets is steeper for diamond than for CZ. (According to Tolkowsky's model of the crown, for a given pavilion angle and girdle thickness). CZs are often cut so that the crown main facets do not touch the girdle. This allows the CZs to have a shallower crown angle, while still having the same crown height as a diamond with a similar cut. \nColor. More precisely, the lack of color: Only the rarest of diamonds are truly colorless, most having a tinge of yellow or brown to some extent. By comparison, CZ can be made in most cases entirely colorless: equivalent to a perfect "D" on diamond's color grading scale. \nThermal conductivity. CZs are thermal insulators whilst diamonds are among the most efficient thermal conductors, exceeding copper. This makes telling the difference between diamond and CZ quite easy for those with the right tools.
814756
or_try_this is correct.  It is dense, and a 30-inch column of mercury fits in a laboratory better than a 34-foot column of water.  It is stable and doesn't evaporate at room temperature.  Its thermal expansion can be compensated for, but it's usually small compared to the pressure differences it's measuring.  It looks scientific, too.
243700
Diamond is (under normal pressure) a chemically less stable form of elemental carbon. In order to synthesize diamond, you need to expose carbon to huge amounts of pressure and considerable heat, as can be found under geological conditions.\n\nSynthetical diamonds aren't fakes, btw.
949928
I think this is an interesting question.  Surprisingly, I think the answer is yes for some properties.  I don't have data in front of me (my books are at the office), but I'll bet that if you compare densities of homologous compounds in a group, you'd find that the density increases along with the density of the main constituent atoms.  I'll also bet that there are spectroscopic properties that are retained -- those relating to the inner shells.  In addition, there are tests used by mineralogists to detect the presence of common constituent metals in different minerals; a common example is the sodium "D" emission that causes a yellow flame in a fire when sodium is present regardless of the counterion.  In inorganic chemistry I seem to remember endless graphs of periodic properties that we used as a mnemonic device, but that was too many years ago to remember them.\n\nIf I wanted to look into it on the internet, I'd do a search on "periodic properties of the elements."  Also, geochemists are wonderful for collecting data and putting together tables of such things, and undergraduate inorganic textbooks may be helpful for finding some as well.
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.
74872
I'm sure this isn't the only material with this property.  \nDo you know what a phase diagram is?  If the line between the liquid and solid phases has a negative slope (goes down as you read it across) like the second phase diagram at this website: http://wine1.sb.fsu.edu/chm1045/notes/Forces/Phase/Forces06.htm\nAny material with a phase diagram that has the line between the liquid and solid phases as a negative slope becomes less dense (expands) when it freezes.  \nThe reason that water expands when it freezes is because when water crystallizes into ice, the structure leaves this pocket of emptyness in the middle of a ring of water molecules.  This makes the ice larger than the water it was when it was liquid.  Anything else that does this will also expand.
916757
Transition metals are stable.  Mercury is a metallic liquid at room temperature.  Diamond and graphite are allotropes of carbon.  H, N, O, F, Cl, Br, I, At form diatomic molecules.  He, Ne,Ar, Kr, Xe, Rn are monoatomic gases at room temp.
388152
What is the hardest mineral in the world? I think that is what you are asking???\n\nThat would be diamond which is composed entirely of the element carbon. It shares the same chemical makeup with graphite which tends to be one of the softer minerals (used in your pencil "lead"). However, diamonds have been exposed to extreme heat & pressure for a very long period of time. That makes the difference between diamond & graphite.\n\nSmaller, impure diamonds are crushed & used on the tips of saws to cut & drill through rocks.\n\nOn Moh's Scale of Hardness, Diamond is a 10, the hardest of all minerals. It will cut through all others.