Oolite Bulletins

http://www.bbc.co.uk/news/science-environment-11942451

was thinking at one point that armour for a Vampire might include a couple-inch-thick diamond windows instead of glass : assuming there's a few of these planets around this could be a feasible upgrade at sensible(ish!) cost.

Killer Wolf wrote:

was thinking at one point that armour for a Vampire might include a couple-inch-thick diamond windows instead of glass : assuming there's a few of these planets around this could be a feasible upgrade at sensible(ish!) cost.

Diamond would make terrible armour – it’s quite fragile, and the shards are sharp.

Ahruman wrote:

Diamond ... it’s quite fragile ...

It is? Isn't it the epitome of hardness on that scratching scale?

So if you threw a diamond against a wall, would it be more prone to shatter or to make a dent? I would have assumed the latter (diamond being near-perfectly dense aligned carbon etc.), and as I am lacking a test object ... I'm asking you from which source you gained the info that diamonds were more in the fragile department.

Curious

L

Killer Wolf wrote:

was thinking at one point that armour for a Vampire might include a couple-inch-thick diamond windows instead of glass : assuming there's a few of these planets around this could be a feasible upgrade at sensible(ish!) cost.

The Pioneer Venus program used a diamond window of approx. 1.8 cm in diameter and a weight of 13 carats. The window was cut in the early eighties of the past century in the Netherlands when I am right. Cost were several million dollar for just one tiny window. They even had to pay import taxes for getting the window into the states, but that tax was refunded after launch.

So nothing new here

Lestradae wrote:

Ahruman wrote:

Diamond ... it’s quite fragile ...

It is? Isn't it the epitome of hardness on that scratching scale?

Yes. Hard and fragile are not opposites. In fact, hard things are more likely to be fragile, while soft things can resist impacts by flexing or deforming.

Lestradae wrote:

So if you threw a diamond against a wall, would it be more prone to shatter or to make a dent?

Why not both?

Lestradae wrote:

I'm asking you from which source you gained the info that diamonds were more in the fragile department.

I’m not sure what my original source was, but:

Wikipedia wrote:

Unlike hardness, which only denotes resistance to scratching, diamond's toughness or tenacity is only fair to good. Toughness relates to the ability to resist breakage from falls or impacts. Due to diamond's perfect and easy cleavage, it is vulnerable to breakage. A diamond will shatter if hit with an ordinary hammer. The toughness of natural diamond has been measured as 2.0 MPa m^1/2, which is good compared to other gemstones, but poor compared to most engineering materials.

Fascinating, Ahruman

Something new learned again

Another Bond movie title debunked! (Diamonds are not forever)

Commander McLane wrote:

Another Bond movie title debunked! (Diamonds are not forever)

definitely not, we dissolved some (industrial) ones during a physics experiment when I was at university.

"Due to diamond's perfect and easy cleavage"

that's the important bit

Killer Wolf wrote:

"Due to diamond's perfect and easy cleavage"

that's the important bit

Diamonds pass my desk on a daily basis, so I have seen quite a lot. In absolute term it may not be the strongest material but in daily use it is. When you have jewelry with sapphires that are used for several years, you can see it on the stones. They all have small nicks on examination. When you examine old diamonds, any defects caused by wearing it, is the exception. In 99+% of the cases the stone is just as new after long use. And when it has signs of wear, it is never a scratch but always a chip off from the stones "girdle".

And cleavage is not that easy. You have to make a V-shaped kerf first. Than you have to place a blunt steel chisel in the kerf that only touches the sides of the kerf. That way generating a sideways force when hitting the chisel. That way the stone is at its weakest.

Related to this topic, and something I've always wondered.

Considering diamond is made of carbon, presumably a diamond would burn like coal?

Anyone tried that yet?

Google is my friend...

Burning diamond...

In a way, it's a shame that finding answers to such obscure questions is now so easy. Takes the fun out of random discussions...[/url]

can't we go back to discussing cleavages? i put that into google and got some fine results.

Killer Wolf wrote:

can't we go back to discussing cleavages? i put that into google and got some fine results.