Talk:Material properties of diamond

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Good article Material properties of diamond has been listed as one of the Natural sciences good articles under the good article criteria. If you can improve it further, please do. If it no longer meets these criteria, you can delist it, or ask for a reassessment.
August 31, 2005 Good article nominee Listed
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[edit] Some questions

First, is there are reason Mechanical properties aren't included in this page. E.g. Compressive Strength / Tensile strength? If not it would be nice to see them added.

Second, will someone please fix or remove the link on the ballas diamonds, it currently takes you straight to Grand Theft Auto. --64.216.141.135 20:40, 1 November 2005 (UTC)


[edit] Hardest naturally occurring mineral?

I may be wrong, but is buckminsterfullerene not harder than diamond...?

It would help if you could provide a source.

In general, the strength or hardness of a material depends on the size of the sample, and the temperature and pressure. If you measure the hardness of a sample with only 60 carbon atoms, you may get very different results than if you measure the hardness of a 1 carat sample (containing 10^22 carbon atoms). For instance, a collection of molecules (each of which has 60 carbon atoms) may be a liquid. Whereas diamond is solid at Standard Temperature and Pressure.

By the way, what is the melting point of buckminsterfullerene?

Unfortunately i am unable to find an Internet based source for this, but i have heard this from many sources, although they may be inaccurate. If anyone can help...

The sources provided in the article presents a modified form of a fullerene, ultrahard fullerite, it may not be naturally occuring. What it does link to is an academic paper, which provides infromation that shows that the engineered substance can under these circumstances, scatch diamond. Though it is physically harder than diamond, Ultrahard fullerite is not made in meaningful enough quantities or avaible in these quantitis in order to be considered a naturally occuring material, if even a mineral. When larger quantities are avaible, we can learn if the microscopic hardness translates to a macroscopic hardness harder than diamond, something meaninful given the current industrial usages of diamonds. --02:19, 21 Jan 2005 (UTC)

Diamond is the hardest mineral substance known to man so you might be wondering why we have a page about chipped diamonds... Well, the key word here is mineral. Contrary to popular opinion, diamond is not the hardest substance in the world. In fact, you can scratch the surface of a diamond with a pop-top from a soda can. Now that we've blown your mind, we might as well finish it off... You can crack a diamond in half trying to scratch glass with it! It's true, if the diamond is at the wrong angle, or if you apply too much pressure, the diamond will cleave in half, maybe worse! Won't little Johnny be surprised when that science experiment fails... "Can Diamonds Be Chipped?" Are these diamond dealers correct in their claims? Can you scratch a diamond using sharpened aluminium or steel? 61.229.142.233 08:10, 12 Jun 2005 (UTC)

I guess Osmium doesn't count as a mineral? "Awesome Osmium" 61.229.142.233 08:10, 12 Jun 2005 (UTC)

I've already responded to most of this at Talk:Diamond#Can't be scratched?, but I'll point out again that the authors of that alarmist page have confused hardness with toughness. If you had read this article, you'd see that diamond's fragility is no secret. The pop-top claim is false; as for osmium (a metallic element, not a mineral), it comes in at only a 7 on Mohs' hardness scale. Your "Awesome Osmium" link again commits a serious lapse in understanding. It is confusing hardness with compressibility. In this respect, osmium is less compressible ("stiffer") than diamond, but certainly not harder. Here's the background information from bnl.gov (PDF file). -- Hadal 03:27, 13 Jun 2005 (UTC)
Thanks for the information and the PDF. [NiceIce, Osmium questions were mine] 61.229.125.147 16:13, 26 Jun 2005 (UTC)

Judging from the article Aggregated diamond nanorods, I think wikipedia is using bulk modulus as the measure of hardness? Even if not, I think a mention of Osmium in various pages including this one is worth it: Osmium has higher modulus than the diamond after all.1wonjae 16:57, 9 August 2007 (UTC)

[edit] Optical properties

What is the transmissivity of diamond (for specified wavelength(s)) through diamonds of specified type, specified color grade(s), and negligible flourescence? An answer that could be converted to units of [percentage of light transmitted through a straight diamond path 1 centimeter long] would be very nice. This would help answer the questions of how Diamond Color affects brilliance and optimum cut. -- Jasper 18:31, 19 November 2005 (UTC)

[edit] Electrical Properties of Diamond

When the article says that you can dope with Boron to obtain a p-type semiconductor but n-type hasn't been fabricated (or found) wouldn't Nitrogen-doped diamonds (yellow) be n-type semiconductors?

Making sufficiently conducting n-type diamond is an open problem. If you dope with nitrogen (or rely on the often naturally incorporated nitrogen), the donor activation energy is very high, at about 1.7 eV (c.f. 0.4 eV to activate boron acceptor dopants), i.e. very few free electrons are created at room temperature. If you move down the periodic table to phosphorus, the activation energy is much lower, at 0.6 eV. Note, though, that it took about 10 years to successfully get active P into diamond. Moving down the table once more, arsenic should have an activation energy of about 0.3 eV, according to theoretical calculations (disclaimer: my theoretical calculations; see my thesis). However, it will be extremely difficult to get the large arsenic atoms into diamond's tight lattice in such a way that they are actually electrically active; most of the time, they will complex with lattice vacancies and be essentially useless. --Steve Sque (I'm mentioned in the references of the main article) --Sque (talk) 17:04, 15 April 2008 (UTC)