Why is sodium chloride said to be very hard?

We can break it easily. Can't us?

Moreover, how can people make graphite?

Is making diamond more difficult or making graphite?

Britleness often accompanies Hardness, a diamond can easily shatter as can Glass, and yet they are quite HARD to scratch.

 

Graphite would be easier to make than diamond as the amount of pressure needed isn`t that great, it`s a naturaly occuring allotrope of Carbon, and quite plentifull. Diamond occures in nature, but only under extrordinary conditions, hence it rarity and value.

Is graphite only the non-metal that is a good conductor?

it`s conductivity is variable, there are others that can conduct a little, not surpisingly called "Semi-Conductors". such as Silicon. although these borderline elements often require treatment (doping) to introduce impurities that allow them to conduct better under certain conditions

a bit random, but also a bit topical:

 

in the news today, there was an article about a new company who will extract the carbon from a dead person and using pressure and heat, turn their remains into a diamond!

so your dead friend/relative can be 'indestructable' for ever!

really!

thanks for that 5614, you`re a Gem

5614, the same thing was in a Finnish newspaper like two months ago, perhaps it came through a rift in time-space. Or then it was another case, though I don't think so such procedure is too common. Either way, it's nice to cut glass with your brother or other relative.

 

"Diamond occures in nature, but only under extrordinary conditions, hence it rarity and value"

 

It's the goddamn DeBeers that makes up the price. "Looky looky, nice stones! Let's raise their price to crazy numbers even though they are quite common!" Rhodium is way rarer than diamonds, and even though it has a price of over 1000$/troy ounce, it can't compete with the diamond price. I'm almost certain that within a couple of decades, the diamond price will decrease rapidly.

Emeralds are the same, gram for gram, worth plenty more than Diamond (even some of the Blue and Pink diamonds) per carrat.

Depends on the emerald, and the diamond. The totally transparent, VVS-grade ones are the kind that cost like hell and the ones Kobe buys for his wife. It seems also that a good grade alexandrite is rather expensive, too. I'd like to have one to my collection because they seem violet under incandescent light, and green under fluorescent light.

 

http://picture.thaigem.com/pics/smallpic/3e/3e1696700.jpg (10x7mm, same gem, different lighting)

 

Price: $12,222.99 at Thaigem. Yipes.

Nice!

 

I wonder if you get a discount for Bulk purchace? )

http://www.thaigem.com/shopping/wholesale/fulldetails.asp?productid=3DJ03492&SORT=start_date&ORDER=desc&CH_PAGENO=1&shape=all&color=&sale_type=1&gemtype=ncs287&pt=&sale_date=&cutadeal=n&healing=&bg_pj=

 

That's one long URL. Go and order two pieces and send the other one to me.

in yer dreams! )

 

 

btw, here`s a tip for you if the URL`s too long, goto: http://tinyurl.com

 

they`ll sort it out for you )

I can't imagine how I have lived my life without the magic of TinyURL! Yay!

...

Yeah.

 

And I of course meant that I would pay for the gem. Like I have with all my gemstones, except the ones I stole. Whoops, don't tell anyone.

 

*Hears sirens and jumps out the window*

Diamonds really aren't that rare. As stated earlier in the thread, it's the DeBeers Cartel that is jacking up the prices of them. There really is no reason why they should be priced so high.

 

Also, graphite is the more stable form of Carbon. A diamond is NOT forever, even though the slogan says so. At room temperature and pressure, diamonds will slowly convert to graphite. However, the speed at which this occurs is so fantastically slow that we really never see it happening.

Diamonds really aren't that rare.

 

in comparison to Graphite it is, and that`s all my post was concerning, it`s natural availability and difficulty in manufacturing

Right'o, chap. Or something. While normal graphite may be easy to make, pyrolytic graphite is a real pain to manufacture since the layer forms like 1/1000 inch an hour. Btw, anyone got a picture showing the structure of pyrolytic graphite?