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Can glass ever can break diamond?

  1. Oct 27, 2009 #1
    I've been thinking about this question for a little while now and figured maybe a good answer here would help to resolve it. Can glass ever break diamond? Some people I know say it's impossible and yet I am left thinking that it is just a matter of how much power is generated by the impact of these two substances.

    If a piece of glass were moving fast enough when it hit a diamond and there was enough concussive energy released from the impact it seems reasonable that glass could break diamond, wouldn't it just be a matter of overcoming some sort of hardness value from the power of impact? If a small piece of glass where fired out of a super powered gun going several thousand miles per an hour, wouldn't it chip or damage diamond. If anyone knows the math, could you show the formula so I could study it?

    Thank you ever so kindly,
    Humble Me
  2. jcsd
  3. Oct 27, 2009 #2
    I am not sure about if someone study therotically about your question but I think energy conversation laws may be a good start for you. In case you should calculate the amount of energy that you need to damage crystal structure.

    By the way it seem possible to me that the idea of " glass can break dimond".
  4. Oct 27, 2009 #3
    I think glass could break diamond - if the glass has enough energy. If a collision between two objects is fast enough anything would get vapourised!
  5. Oct 28, 2009 #4
    OK, I will look into getting started in studying energy conservation laws, is there a good link or source already on the internet somewhere anyone can recommend.. I remember taking classes back in college and Uni, but I don't remember everything I learned because I haven't used much of it in my work. I loved my physics courses, I got A's, and my physics professors often told me I should be a scientist because I seemed to have a knack for physics. There is no point fretting that I went another way, but I like to think it isn't too late to change course and I've been longing to get back into physics.

    One idea I've had for a while is to collect many formulas on a large poster where I can easier memorize them and work with them while doing experiments of my own that are within reach. Any advice given here will be taken seriously and likely worked with if the leads pan out.

    This was my thought as well, it seems almost obvious that it is just a matter of how much power is generated by the impact, which is a matter of weight multiplied by speed divided by surface area of the colliding objects, in this case glass and diamond. I can't remember the exact formulas, and knowing what the resistance factors are to overcome for impact to damage or destroy is also something that slips my mind.

    One thing I am curious also about is if the glass could gain enough speed before breaking down, though I imagine this has a lot to do with its shape and size. A huge heavy ball of glass obviously can move faster without breaking down then a thin sheet like a window. If it moved fast enough would it melt from friction or shatter or a little of both...certainly yes, but if going just under it's maximal speed before breaking down would it be enough to damage diamond, I think so...I think also that since the amount of energy generated by impact is a matter of size and speed, given that the glass is big enough it would damage diamond.

    Then again there is the possibility that if the glass is too big and not moving fast enough the diamond would cut into it without taking damage...like a bullet goes into an apple for example. I'm sure this can be calculated in advance to make a high success rate for predicting an outcome based on initial conditions.
  6. Nov 5, 2009 #5
    I don't actually see how glass could break diamond. The covalent bonds in carbon make it extremely hard to break and the bonds in glass are far weaker. What you are saying is that the strength of these bonds will not make a difference so long as the speed of the glass is high enough. But surely the glass will crush as soon as it touches the diamond? Its like trying to stab a diamond;the blade will bend before it cuts the diamond.
  7. Nov 6, 2009 #6
    like Akb2793 said the bonds in the diamond are much stronger than that of glass so when the glass and diamond collide this energy would just go into breaking the bonds in the glass as opposed to the diamond. but im not sure someone else will have a better answer im sure =]
  8. Nov 6, 2009 #7


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    akb2793 and matt_crouch, I'm interested in how you think diamond gems are created. (From a blade of uber-diamond?) They don't come out of the ground faceted.

    Can a material have strong atomic or molecular bonds (i.e., be very stiff) and yet still break easily?
  9. Nov 6, 2009 #8
    erm materials can be brittle but honestly im not sure
  10. Nov 7, 2009 #9


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    Here's a question: glass is much harder than leather - so can a baseball break a window?
  11. Nov 7, 2009 #10
    You are breaking the crystals through planes not the bonds. I think you should look into crystal structure and planes of diamonds that should answer your questions.
  12. Nov 7, 2009 #11


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    diamond has some pretty perfect planes of cleavage. Whack a diamond on any hard surface, and you can get a chip.
  13. Nov 7, 2009 #12
    A diamond is brittle. A hammer can smash a diamond to dust. Take two blocks of glass; hammer and anvel, and smash-away. Don't try this at home.

    :blushing: this thread is 10 days old. Oh well.
    Last edited: Nov 7, 2009
  14. Nov 17, 2009 #13
    Note that glass hitting diamond really fast is the same thing as diamond hitting glass really fast (i.e. Newton's Third Law).

    You need to define the problem more clearly (specifically size scales). Otherwise, a structurally sound piece of glass could damage a structurally weak piece of diamond.
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