What is Diamond: Definition and 112 Discussions

Diamond is a form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. At room temperature and pressure, another solid form of carbon known as graphite is the chemically stable form of carbon, but diamond almost never converts to it. Diamond has the highest hardness and thermal conductivity of any natural material, properties that are utilized in major industrial applications such as cutting and polishing tools. They are also the reason that diamond anvil cells can subject materials to pressures found deep in the Earth.
Because the arrangement of atoms in diamond is extremely rigid, few types of impurity can contaminate it (two exceptions being boron and nitrogen). Small numbers of defects or impurities (about one per million of lattice atoms) color diamond blue (boron), yellow (nitrogen), brown (defects), green (radiation exposure), purple, pink, orange, or red. Diamond also has relatively high optical dispersion (ability to disperse light of different colors).
Most natural diamonds have ages between 1 billion and 3.5 billion years. Most were formed at depths between 150 and 250 kilometres (93 and 155 mi) in the Earth's mantle, although a few have come from as deep as 800 kilometres (500 mi). Under high pressure and temperature, carbon-containing fluids dissolved various minerals and replaced them with diamonds. Much more recently (tens to hundreds of million years ago), they were carried to the surface in volcanic eruptions and deposited in igneous rocks known as kimberlites and lamproites.
Synthetic diamonds can be grown from high-purity carbon under high pressures and temperatures or from hydrocarbon gas by chemical vapor deposition (CVD). Imitation diamonds can also be made out of materials such as cubic zirconia and silicon carbide. Natural, synthetic and imitation diamonds are most commonly distinguished using optical techniques or thermal conductivity measurements.

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  1. W

    I Melting point of graphite and diamond?

    I was conversing with ChatGPT when I asked which material has the highest melting point, and it answered "tungsten" (giving its melting temperature). It so happened that in the previous question the melting point of graphite had come up, and it was listed as higher than that. When I asked which...
  2. I

    Exploring Tetrahedral Stacking in Diamond Cubic Arrangements

    In terms of tetrahedral stacking, as occurs in diamond cubic, what I'm describing would be a system with additional tetrahedra in the empty cubes of that figure, but with their vertices on the opposite corners of the cubes that contain them to the "regular" diamond cubic arrangement. Due to the...
  3. U

    A Wigner–Seitz cell of diamond

    Hi everybody, I'm struggling with some solid state physics topics. I am dealing with the Carbon diamond crystal structure, which is basically made of 2 FCC compenetrated. I really cannot visualize the Wigner–Seitz cell of this structure, is it possible to do it? I was thinking about visualizing...
  4. K

    I Uncovering the Truth: Jupiter's Core Revealed as Solid Diamond by Tammy Ma

    In a recent Scientific American article, Tammy Ma claims Jupiters core is solid diamond. She claims her work with lasers has demonstrated this. Any thoughts?
  5. P

    I Primitive unit cell (Diamond)

    Hi guys , I want to construct a primitive unit cell for diamond, which is made of a fcc lattice and a basis of 2 carbons atoms. I know that a primitive unit cell isn't unique but the two variants I get are drastically different . As far as I can see they both include 2 whole atoms/points in the...
  6. R

    Chemical Vapor Deposition - Diamond

    Are there any instructional video's on how to make your own CVD Diamond optics. I was looking online and CVD Diamond wafers are EXTREMELY expensive. Is it possible to make a plasma chamber for CVD if so does anyone have any good text recommendations What is the catch
  7. I

    I Center of inversion of cubic diamond structure?

    I'm having hard time finding the center of inversion of cubic diamond structure. At first I thought (2,2,2) would be the center of inversion, but (1,1,3), (3,3,3), (1,3,1), (3,1,1) (i.e. four atoms inside the cube) are not centrosymmetric about (2,2,2).
  8. B

    I Infrared emission by diamond

    does anyone know what is the average angle of infrared emission is by a flat diamond surface or tha directional distrabution
  9. K

    A Symmetries of a Diamond Unit Cell - Point Group Confusion

    Dear All, I've been recently reading the very clear text of Burns and Glazer entitled Space Groups for Solid State Scientists in the context of my thesis which requires understanding of symmetries of crystals, more specifically symmetries of (approximate triply periodic minimal surfaces)...
  10. V

    Diamond/Silicon's band structure

    Homework Statement I am asked to discuss the band structure of diamond. I saw the band structure of diamond has 4 filled valence bands and then 4 conduction bands. Silicon, the same. Homework Equations --- The Attempt at a Solution I'm feeling really silly because I don't understand why it is...
  11. N

    How is this diagram of the structure of diamond correct?

    see this diagram of the structure of diamond given in my textbook- I have read in my textbook that each carbon atom in a Diamond crystal is attached to four other carbon atoms by strong covalent bonds.But, in the diagram above I can see that some of the carbon atoms are not attached to 4...
  12. I

    B How can one turn diamond powder back into hard stone form

    I have some diamond powder and was wondering how I can turn it back into its hard stone form? What can I do. I'm a hobbyist chemsit/physicist. I just need some help from more knowledge people
  13. Lacplesis

    Diamond vs. glass -- thermal properties

    Hi, I was reading up on the properties on various materials but never quite found out what I was looking for. My question is this , I found out an explanation why diamond is the best thermal conductor even though its not a metal and why other materials that would be similar to diamond like glass...
  14. J

    I Nitrogen-Vacancy centres in Diamond for NMR spectroscopy

    Hello, I have been looking into NV in diamond and how it can be used for nanoscale magnetometry, and was wondering if anyone could help explain how it works or link to a paper that does. Is it just a spin 1 state (splits to 3 levels) that undergoes NMR or is there something else happening? I'm...
  15. Aafia

    Can Diamond be melted in thermite reaction?

    My books says Thermite reaction is an exothermic reaction, it release large amount of heat so that temperature increases upto 3500°C On the other hand it is written Melting point of diamond is 3500°C So my question is whether diamond can by melted in such reaction?
  16. G

    A Limiting factors in Diamond Anvil Cells

    Hello, I'm trying to better understand the limiting factors in Diamond Anvil Cells that limit the achievable pressure to around 7 or 8 Mbar at the moment, despite not being a specialist. For example, is there a special reason other than the tiny size of the crystal sample used in DACs for why...
  17. B

    I Helium Ion collision with diamond wafer

    If a Helium ion He+ collides with a diamond wafer surface, an insulator, does the Helium ion, at 25 deg C, will the ion lose it's charge by gaining an electron from the insulative surface or does the ion have an elastic collision with no net energy loss or gain?
  18. T

    New research or uses of diamond?

    I am not sure if this is the right forum to put this on so sorry in advance: Hello, I am currently researching about diamonds. Could someone tell me any new research, technology or uses of diamond? I have tried googling and haven't come across much. Thanks!
  19. T

    Why is diamond stronger than metals?

    I know the reasons that diamonds are stronger than covalent materials and ionic compounds. The former is weaker because there are intermolecular forces and the latter is weaker because if pressure is applied like charged ions would be forced together making it brittle. However, I cannot think...
  20. MDM

    Calculating the Heat Capacity of Diamond

    Homework Statement Heat capacity is the ability of the material to store energy internally. If I completely insulated diamond and I put heat into it, It would have the ability to store 6.57 (Joules/mole) per degree Kelvin. Use this formula q=Cp (ΔT/ Δt) where q is heat in Watts, ΔT is...
  21. U

    Surface density diamond structure [1 1 1]

    Homework Statement Calculate the surface density (planar density) of the Silicon diamond structure in the [1 0 0],[1 1 0],[1 1 1] planes. Given a = 5.431 A (latice constant) Hint: For the (111) plane, it should help you to think of the diamond lattice as two interpenetrating FCC lattices.2...
  22. Jimster41

    Looking for an explanation/definition of a "causal diamond"

    hopefully something a little better than the wiki etc. What does a "deformed" one look like, or one drawn in the case of EPR, entanglement etc.
  23. J

    Optical phonons in fcc-lattice

    Aluminium has an fcc structure, which is a simple cubic lattice with four Al-atoms in the basis. On the other hand, diamond has a diamond structure, which is a simple cubic lattice with 8 atoms in basis. Now, diamond has optical modes in addition to acoustical, while Aluminium does not. What...
  24. Greg Bernhardt

    AudioQuest Diamond: most expensive HDMI cables worth it?

    I was browsing amazon for some basic HDMI cables and was flabbergasted when I came across some by AudioQuest Diamond. They cost $1,494.75 for 6.5FT. https://www.amazon.com/dp/B003CT2A2M/?tag=pfamazon01-20 The information gives Solid Perfect-Surface Silver (PSS) Conductors Low Jitter, Low...
  25. Planetx

    Can a 50 Caliber Bullet Penetrate a Pure Diamond Plate from 50 Yards Away?

    How thin would a pure diamond plate have to be cut for a bullet to penetrate or fracture the plate if shot from a 50 yard distance? (assuming it is a spot on shot and the plate is octagonal and 15 cm across, and the bullet being a standard 50 caliber round.)
  26. J

    Would a pure diamond drill bit ever get dull?

    If a drill bit that was cut out of a single large diamond were made, would it last forever, assuming it was never used to drill through diamond and was never exposed to a laser? Would it ever get dull or break?
  27. S

    Do diamonds reflect EM waves ?

    Radio or any other wave in electromagnetic spectrum? Sound perhaps? And at what frequency(ies)
  28. G

    Why diamond is a hardest structure

    Why diamond lattice structure is a hardest (?) one? If it is because each atom connected to 4 adjacent, then why simple cubic, where each atom connects to 6 adjacent is not the case? And why ZnS having the same geometrical structure is not as strong as, say, carbon, or silicon diamond? Thank you.
  29. C

    Diamond Circuit, Three EMF Sources -- Parallel?

    Hi, Is the circuit in the attached image essentially one with three parallel branches, each with a different source of emf and two resistors? ie, ε1, R1, R2 on one branch, ε2, R3, R4 on another, and similarly for the last one? Thanks!
  30. B

    Verifying That Diamond Is More Stable At Certain Conditions

    Homework Statement Verify that diamond becomes more stable than graphite at approximately 15 kbars Homework Equations The Attempt at a Solution So, I understand that to show one substance is more stable than another at particular environmental conditions, I just have to show...
  31. B

    Solid State: Diamond lattice and scattering

    I have the following homework question I am working on. I am given three scattering angles: 42.8, 73.2, 89. (in degrees) without the wavelength of the light used. I am to show that these are consistent with a diamond lattice. I started with Laue's Law: delta(k) = G and according to the...
  32. S

    Carbyne - New Carbon Allotrope Stronger Than Diamond, Graphene

    Carbyne is comprised of chains of double- and triple-bonded carbons and is believed to be stronger and stiffer than graphene, nanotubes, or diamond: http://www.technologyreview.com/view/518301/new-form-of-carbon-is-stronger-than-graphene-and-diamond/ To me, this reminds of Arthur C Clarke's...
  33. Petrus

    MHB Show that diagonals in a diamond (rhombus) are orthogonal

    Hello MHB, I am working with a exemple that I think they got some incorrect. Exemple 10.Show that diagonals in a diamond(romb) is orthogonal. I understand that AC•BD=0 cause of dot product and if it's orthogonal the angle is \frac{\pi}{2} I understand all the part until the step before the last...
  34. R

    Volume of Diamond Unit Cell

    I have some difficulty understanding how the volume per unit cell for the diamond structure is calculated. I've seen in various websites that this volume is: ##v=a^3 = \left( \frac{8r}{\sqrt{3}} \right)^3## Here ##r## is the radius of an atom. But how did they work out ##a## (the edge of the...
  35. A

    Why does the melting point of graphite is higher than diamond?

    In diamond valence electrons are fully covalently bonded.But in graphite only three are covalently bonded while one electron is freely moving.So it seem that melting point of diamond should be higher than that of graphite because in diamond we should break four covalent bonds while in graphite...
  36. E

    MHB Probability that 12 have purchased yellow gold diamond rings

    Let’s also say that 65% of all diamond rings sold in WV are yellow gold. In a random sample of 20 folks, what is the probability that 12 have purchased yellow gold diamond rings?thank you and I promise this is the last question today.:D
  37. 4

    What is the estimated worth of a planet made entirely of diamond?

    Planet PSR J1719- 14386 is a planet completely made of diamond. I've wondered what the estimated worth of the planet's material, perhaps you guys know?
  38. M

    Bands, Energy diagram in a diamond

    Homework Statement The gap between valence and conduction bands in diamond is 5.47 eV. (a) What is the maximum wavelength of a photon that can excite an electron from the top of the valence band into the conduction band? In what region of the electromagnetic spectrum does this photon lie...
  39. zoobyshoe

    Russia Sitting on Massive Diamond Find Since the 1970's

    http://news.yahoo.com/russia-reveals-shiny-state-secret-awash-diamonds-131212873.html [Broken]
  40. J

    Bonding of Diamond: Unreactivity & Impurity

    Homework Statement Hi, there are 2 pictures in the above,pic 2 shows a diamond in rectangular shape. pic 1 shows the 3D structure of that diamond at a corner of it. As we know,diamond has a giant covalent structure,which means atoms in it are linked together by covalent bonds only...
  41. S

    True black carbon in diamond from an image

    I have difficulties in finding the true black carbons in a diamond from an image. Since diamond has a high refractive index of 2.42, it has a critical angle of 24 degrees such that total internal reflection can easily occur (total internal reflection causes fire in diamond) . Now I have...
  42. 4

    Diamond light energy reactor.

    Hi guys I wonder if anyone could help me help my son create an energy source for his school project. All my son is allowed to use (he doesn't have to make it just proove it might work) is a perfect diamond with 6 equal sides all lengths the same size (like 2 pyramids base to base), Matter...
  43. R

    Final temperature of diamond using Cv

    Homework Statement At low temperatures, Cv of solids is given by: Cv = D(\frac{T}{\Theta})3 where: D = 1.94*10^3 \Theta = Debye Temperature, for diamond 1860K If 100J of heat is transferred to 1mole of diamond, initially at 10K. Calculate the final temperature. Homework...
  44. B

    Can High Pressure Create Diamonds in Nature?

    Ok, I understand the difference between diamond and graphite but how is it that diamond actually forms? Why is that carbon forms one way at one time and a different way at another time? My best guess is that you have to subject the carbon to enormous pressure because it looks like diamonds...
  45. A

    [School project] Making diamond

    Hey there, First of all I want to apologize for my English, haha. So for a project I came up with the idea of making diamond. It sounds a bit impossible, but I've found some good theories (and proven) experiments. 1 is with pure alcohol, and the other one is about making diamond with a...
  46. H

    Diamond vs graphite by a conductivity?

    Diamond vs graphite by a conductivity? Hello. This is the last question on HW. Q) Diamond and graphite are both made of carbon atoms. Explain why diamond is elecrically insulationg while graphite is a good conductor in terms of type(s) of hybridization of atomic orbitals and bonds in each...
  47. rhody

    Diamond Planet, a woman's new best friend

    http://news.cnet.com/8301-17852_3-20097817-71/astronomers-weve-found-a-planet-made-of-diamond/" I have absolutely no prediction about this thread, and with the cast of regulars we have here at PF, am hoping it will generate some funny, interesting discussion. Pengy, Jimmy, Evo, Lisa are you...
  48. Orion1

    PSR J1719-1438: The Planet-Sized Diamond in Space

    https://www.youtube.com/watch?v=ylGwsIIyZf0 Reference: http://en.wikipedia.org/wiki/PSR_J1719-1438" [Broken]
  49. D

    How to prove there is no primitive cell of diamond structure with only one atom?

    How to prove there is no primitive cell of diamond structure with only one atom? Thanks in advance!
  50. H

    Probability of a drawn card be a diamond given post conditions

    Setting is like this: I have 52cards of 4 shapes. that's 13 each. I take one card out and put it in a hat. now with 51card I draw 3 consecutive cards. It happens to be that I picked 3 diamonds. Now I want to find the probability of the card in the hat be a diamond. My friend said it...