what are the factors that influence bond strength and mineral hardness both?
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Bond strength is influenced by how the atoms combine together. I like to think of it like construction of a building. Some buildings are sound b/c they have been solidly constructed while others are flimsy.\n\nSome silicates are bonded together like sheets. There is a network of flat well bonded molecules & in between a weak bond w/ the next layer. Example is mica. It will peel apart into very thin sheets.\n\nB/c some minerals' atoms are bonded together ratherly compactly & tightly, it allows them to be a little more sturdy. They have a strong bond & excellent framework of sturdy construction.\n\nThis also affects whether a mineral will fracture or cleave. When broken some minerals will break unevenly into pieces like quartz. It makes conchoidal fractures. Galena however will break into nice little cubes. This is called cubic cleavage.\n\nIts always fun trying to explain fracture & cleavage to a bunch of hormone raging 14/15 year olds! LOL.
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Titanium with special alloy bolts so saltwater doesn't corrode. Light weight for its strength.\nSome deep sea are silica glass. The strength increases as the compressive loads are applied.\nCheck Jacques Cousteau. He made some special deep diving.\nWoods Hole Oceanographic Institute has Alvin.
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According to the Mohs scale, diamond is the hardest mineral.  I believe that a harder mineral can scratch a softer mineral as well as itself.  So that would work.
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Ionic bonds have really different electronegativity to the point where one atom really takes the electron and the other atom readily gives the electron.  Therefore, 2 ions (or more) are formed with opposing charges.  Since they are opposing, what happens is that they will be really stuck together at a fixed position.  Therefore, no sliding will occur.  The material will be brittle.  Fine examples are salts and rust.  If and when dissolved in a solvent, the ions seperate and yet maintain their charge.  Ions can come from a group of atoms (molecule) like CN or a single atom H.  But the results are not atoms, but ions such as CN- and Na+ (NaCN), which individually C and N of the CN- are not the ions, but the CN- is considered the ion.  Other examples of this is CO3 2- and Ca 2+ which together is CaCO3, a salt; again, the Carbon and the three Oxygen atoms are not the ions, but the group itself is considered an ion.\n\nCovalent bonding occurs between two atoms that are willing to share the electrons.  Sometimes, due to difference in electronegativity, there are unequal sharing but nonetheless sharing; note the difference cannot be to high or you'll get an ion.  Atoms are can be easier to slide like in a metal or be really difficult to move (like in silicate oxides and diamond).  It all depends.  Since there's a sharing of electrons, it is possible to have a dipole-dipole moment where electrons could concentrate themselves at one end or the other of the molecule; that is why I2 exists as a liquid, because of the looser valence electrons, there is a tenadancy for the electron density to shift from one to the other atom causing a propagative effect to other neighboring I2 molecules, which is the reason why it's the only diatomic molecule to be a liquid from all halides.  CN- has a covalent bond (triple bond).  CO3 2- also have covalent bonds.\n\nLooking at the periodic table, the electronegativity of a an element increases from the bottom to the top row and from the left to the right column (w/ exception of noble gases).  That means that the halides are extremely electronegative, which means they love electrons.  But, as you go down the list of halides, they love electrons less and less due to electron shielding - there are other electrons that are closer to the nucleus lessening the effective nuclear charge that is reaching the valence electrons.  Therefore, those electrons can be stripped from those heavier halides (like Iodine) as opposed to the halides that have less orbitals filled (like Fluorine).
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NaCl, the bonding is stronger
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bond length:\nCO  CO3(2-) CO2\n\nBond Strength:\nCO2   CO3(2-)   CO
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Hardness Mineral Absolute Hardness \n1 Talc \n(Mg3Si4O10(OH)2)\n 1 \n2 Gypsum (CaSO4·2H2O) 2 \n3 Calcite (CaCO3) 9 \n4 Fluorite (CaF2) 21 \n5 Apatite \n(Ca5(PO4)3(OH-,Cl-,F-))\n 48 \n6 Orthoclase Feldspar (KAlSi3O8) 72 \n7 Quartz (SiO2) 100 \n8 Topaz (Al2SiO4(OH-,F-)2) 200 \n9 Corundum (Al2O3) 400 \n10 Diamond (C) 1500 \nIt goes from the level of hardness to a mineral and absolute hardness.
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Mohs' hardness scale is somewhat arbitrary.  Moh tried to find commonly available minerals that were about equally spaced in hardness.  Talc was arbitrarily assigned "1."\n\nAs one example of the inconsistency, diamond (Moh's 10) is about 10 times harder than corundum (Moh's 9).\n\nThere should be some minerals sites out there that allow you to list minerals in order of Moh's hardness.  There may also be some with Vicker's hardness for comparison.\n\nThe main advantage of Moh's hardness scale is its practicality for field use.\n\nA lot of the sheet silicates are very soft.  In the soft ones, the only forces holding the sheets together are van der Waal's forces, which are quite weak.\n\nClays are very soft.  The crystals are very small and only van der Waals forces act between them.  (They are also sheet silicates, but the sheets are held tightly together by cations.)
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MgO and Al2O3 have greater ionic character than SiO2. A compound melts when the lattice breaks down and a lattice breaks down when the bonds holding it in place give way.\n\nIonic bonds are stronger than Covalent ones.\n\nThere are some amorphous forms of SiO2.\n\nYes, an insulator can conduct under such conditions.
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Hardened concrete strength depends on the water to cement ratio (w/c ratio). Lower the w/c ratio, higher the concrete strength. This is because excessive water in concrete may create water pores and void in the concrete which will affect concrete strength.\n\nBut the problem is when we use lower w/c ratio, workability of the concrete will be very poor. Increasing the use of water in other hand may improve workability but increases w/c ratio. By adding superplasticizers into fresh concrete, it can improve workability and maintain optimum w/c ratio.\n\nAlthough plasticizers cannot directly improve the strength of hardened concrete, it promotes workability, thus enable concrete to have lower w/c ratio.\n\nMore technically, superplasticizers interact with wet cement particles and produces a membrane of absorbed charged molecules around each particles, with prevent the cement from flocculate or become sticky.
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The hardness of general materials such as minerals is often compared to a list of materials on Mohs hardness scale which runs from talc (softest) to diamond (hardest).\n\nMany metals are checked for hardness by measuring the resistance to a small spherical or diamond shaped stylus as it is pushed (impressed) into the metal.  There are numerous scales available depending on overall hardness of the metal in question (and the testing machines readily available).
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It all depends on the metal.\n\nSome metals are soft in nature, but when alloyed with others can become very hard and strong.  Combining iron and carbon with Molybdenum and Nickel can make a very hard, but brittle steel.  \n\nCopper by itself is very soft and easy to work.  Combine it with tin and you get Bronze (a harder metal) or with antimony to get brass (harder still).\n\nHeat treatments also affect the hardness.  When a metal is heated, the crystals essentially "reset" themselves to be in an amorphous state.  A rapid cooling such as a water or oil quench will cause small, tightly packed grains, creating a hard metal.  A slow cooling will result in a softer material that is easier to work with.
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True: in the same set of conditions, minerals will be unique in their properties including electrical conduction, hardness, light reflection, ect. Minerals can be in different forms though, which you should always take into consideration.
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Color, shape, hardness, melting point, boiling point, density
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See the two references below about metallic bonds.  The explanation is a little too long to type in this tiny space, but the first reference explains why gold is soft and both of them explain why it is a good conductor of electricity.\n\nTypes of bonding page 4 and Metallic bonds page 5: http://www.encyclopedia.com/doc/1E1-chem-bnd.html\n\nLast section on metallic and hydrogen bonds:  http://www.encyclopedia.com/doc/1E1-chem-bnd.html
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It determines the number of ligands the ion can be surrounded with, both in the crystal and in solution. (Electronic configuration dictates the likely geometry.)\n\nThere is no direct correlation. Stability of the salt depends among other factors from the ionic character of the salt - some of the badly soluble sulfides have bonds with covalent character.\n\nThe energy gain from dissolving the salt (allowing free movement of formerly ordered crystals) has to be greater than the energy required to leave the crystal. Usually the ionic ligands in the salt crystal are replaced by water molecules.
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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.