In the course of a family conversation, my brain spit out one if its random, useless bits of trivia:
“If you put a diamond into an oven, it’ll slowly burn into CO2, eventually completely evaporating”.
Well, there was some doubt about this, and I honestly can’t remember where I picked it up, so I tried some research: first in the SD article archives, then in the SDMB search (although it looks like there’s still some archives that need to be indexed), then snopes, then google. I couldn’t find anything authoritative. The best I could find was a post on a ceramics message board about not being able to use diamond dust in a glaze, since the heat from a kiln would be enough to get the dust to a point where it oxidizes into CO2. A post on sci.physics mentioned that at around 1000C a diamond’s surface would break down into graphite, which would in turn oxidize into CO2. But the story I remember hearing specifically mentioned an average home oven, which would have a much lower temperature than that, or even a pottery kiln.
So, here’s what I’ve got:
Diamond is pure carbon (not worrying about foreign material that may be in it)
Carbon + atmospheric O2 = CO2.
Diamond is apparently slightly unstable at the heat/pressure found on the earth’s surface, although this instability would require geologic time to noticably manifest. Basically like how glass is supposedly a “very slow-flowing liquid”.
Questions:
A) Would the temperatur in a conventional home oven be enough to break the carbon bonds in a gem-sized diamond?
B) What would the rate of “sublimation” (best word I can come up with) be at say 400F (205C)?
C) Am I guilty of passing on an urban legend (or at least mostly incorrect information)?
D) If it turns out that this is possible, any cites I can pass along so my family has less ammunition for my commital?
I’d have to say you’re misinformed. Diamonds have a thermal rating about four times higher than copper, yet copper is commonly used in cooling utensils due to it’s thermostability.
This site has a diagram of diamond structure undergoing melting at a temperature in excess of 4000K or 6740F, a much higher temperature than your home oven can achieve. http://cmp.ameslab.gov/cmp/CMP_Theory/tb/amorphC.html
My understanding of physics is limited, but I think that a diamond will eventually evaporate into gas at room tempurature-- it just takes a really frickin’ long time.
When people burn diamonds, they usually immerse the gem in liquid oxygen, to encourage rapid oxidation.
And by the way, I thought I’d seen everything until I found that you can buy water carbonated with diamond fumes. http://dreammaui.com/diamondwater.html
This page is by a master jeweler, who goes on to explain about solder heat and steps taken to prevent high-temperature soldering (during prong retipping, mostly) damaging diamonds.
A) Not likely, Mp = 3550 Celcius, Bp = 4827 Celcius
B) Longer than a week - Diamonds slowly change to graphite (a more stable form of solid carbon - but can sublime at high temps)
C) Only about the glass-flowing thing
D) Diamonds aren’t forever, graphite is
Thanks for the info, I guess that’s one more useless fact marked “sounds plausible but wrong” in the fragmented hard drive of my mind.
So just to try to retain some credibility, it would happen, but it requires higher heat than most people have access to and probably a more oxygenated atmosphere?
And I am smacking myself for the “flowing glass” comment. Should’ve specified that as “similar to the incorrect belief that glass flows”. Yeah, yeah, that’s what I meant.
Shoot, hate knocking off whatever credibility you have, but the amount of oxygen in your hourse shouldn’t be a problem, but you are right about the heat (but if you get a barbeque set with that kind of output, let me borrow it )
)