when a sone is said to be a diamond?

[coolguynamek]

I would like to know When a stone is said to be a diamond.. diamond hardness is 10 ruby/corondum/sapphire hardness is 9. diamond can scratch a ruby but a ruby cannot scratch a diamond .. that only test seems to be taken in to consideration ? .. I think lot of other things has to be taken to test a stone to be a diamond..

Let me know some comments from our experts gemmologist and collectors ...

coolguy..

 

[GLudlow]

www.dictionary.com
An extremely hard, highly refractive crystalline form of carbon that is usually colorless and is used as a gemstone and in abrasives, cutting tools, and other applications.

There ya go!

 

[pyramid]

coolguynamek

This is the way of describing a diamonds hardness and was devised by a Mr Moh and is known as the Moh's scale whereby those at the top of the scale can scratch those below but not the other way around.

This is not I believe how diamonds are tested, I am just a consumer but I believe gemologists have other ways of testing stones with new technology and also probably by their experience in identifying inclusions or crystal growth under the microscope.

Maybe one of the experts here can tell you. I believe I have seen it written that the best way to know you have got a diamond is to get it tested by an independent appraiser or gemologist.

 

[DiamondExpert]

Are you asking about an uncut or polished diamond? Either way, the way they are detected in mining is by X-ray fluorescence.

Polished stones are usually identified by using a diamond tester which measures thermal (and sometimes electrical) conductivity (caveat - synthetic moissanite also tests + with some of these instruments, but is doubly refractive), and by looking at it at magnification - with experience it is usually fairly simple to identify a diamond. Diamonds are great thermal conductors and (except for some of the more rare sub-classes) and lousy electrical conductors.

The last thing one would do is start scratching things with other things - especially valuable stones!

 

[mogok]

Hello,
Gemstone identification in gemology use non destructive methods to identify gemstones. The hardness test is never performed to identify a diamond. Diamonds have many other physical and optical caracteristics that make them different from any other stone. And each stone can be identified without damaging it using standart gemological instruments:
Microscopes, loupe, refractometer, polariscope, conoscope, dichroscope, color filter, hydrostatic balance, UV light...
or advanced laboratory instruments such as Infrared, Raman, UV spectroscopy, XRay fluorescence.

Diamond are very easy to identify for a specialist. As easy as to say this is a girl or a boy when you look at people in the street!
All the best,

 

[coolguynamek]

I can agree with your points ... But still, Stone not showing its brilliance but its harder then any other stone. Still can we say its a diamond...

Nowadays gemmologist has come up with no of testing.. for any stones.

coolguy

 

[WinkHPD]

Not sure of your point. If the stone is not showing its brilliance, why not? Is it opaque? is it rough? even so there would be other ways of testing, such as the specific gravity of the stone. Why would you want to rely on a scratch test? Why are you wanting to limit it to this test?

Wink

 

[HollyGo-Lightly]

It's it's made up of carbon in the exact pattern that makes it cubic. Graphite is made of carbon, but it's internal structure is different than diamond, and it's hardness, color, toughness and specific weight is different.

Also, I believe diamonds can be tested by their refractive index (2.417), their dispersion (can't find that number right now), and specific gravity being 3.52 (plus or minus .01)
Also cleavage when cutting into the rough is perfect in four directions, plus it has a thermal inertia that is higher than any of the other stimulants, such as Moissantite and CZ, or even the other colorless gems that can be faceted...

Each simulant has a tast for it, against diamond, and each of these tests are what make the diamond a diamond.

It's like saying if something barks, and it has fur and four legs it is a poodle. No, it has to actually have certain characteristics which can be tested, or even genetics.

Same with diamonds, except you can't interbreed a diamond (I don't think!) half poodle, half diamond? Talk about a girl's best friend!