how is it possible to scratch a diamond...

[Dancing Fire]

if diamond is the hardest substance in the world?

 

[kenny]

Equally hard substances can scratch each other, so any diamond can be scratched by another diamond.

That's why it astonishes me when I see pic of polished diamonds in a container together.

 

[oldminer]

The hardness of diamond is directional. If a hard direction moves a softer direction of another diamond, you might get a scratch. There is not much difference in this hardness, but a little goes a long way.

 

[yssie]

That's interesting OldMiner. What causes the harder and softer areas/directions, could you elaborate on that? Or if you know an article off-hand.

Moh's dictates scratch resistance - it's not an absolute scale though. Durability issues due to inclusions, cleavage & chipping (isometric crystal with four-direction cleavage) is another issue - diamond material would make for poor rope or bricks because of this cleavage pattern.

 

[MichelleCarmen]

There is a story in a diamond book I have where a person found a colorless stone somewhere (a safe?) and wasn't sure if it was a diamond and had heard that diamonds cannot be scratched, so the person tested that out and the stone DID scratch yet turned out to be a diamond (now with a decorative line across the table) lol

ETA - this is a true story, not in a novel...

 

[denverappraiser]

This directionality is the secret for to how to cut diamonds. 'Cutting' doesn't involve a knife like tool the way most cutting is done but rather involves a spinning table that has other tiny diamonds impregnated on it. They use this to abrade away the material. The cutter carefully positions the stone to be cut so that the small stones on the grinding surface are rubbing against it in the 'soft' direction and individually polishes each facet this way. It can be a very tedious process. It's part of the reason that cutting diamonds is a whole different art form from cutting any other stone and involves specialist artisans, special tools etc.

 

[Dancing Fire]

The hardness of diamond is directional. If a hard direction moves a softer direction of another diamond, you might get a scratch. There is not much difference in this hardness, but a little goes a long way.

if the surface of a diamond never came in contact with another diamond can it still get scratches from everyday wear?..

 

[kenny]

So in the hard direction diamond is Mohs 10, (Max on the hardness scale) but in the soft direction it is 9.9862, or something?

 

[MissGotRocks]

My first stone had a multi line scratch across the table after wearing it for a few years. It would have reminded you of something scraped across a brick or something. It had not been scratched across anything to my knowledge but the scratches were there nonetheless. I really didn't think about it at the time and traded it in although it wasn't worth much and the new stone was far more money so I'm guessing the person I traded it to didn't care about it anyway. That was many years ago too!

However, now I realize that scratching that stone would have been very hard to do. I even wondered if it was a diamond but it had a pretty good inclusion near the girdle so I'm sure it was. Never figured out that mystery!

 

[Luminous-MB]

The hardness of diamond is directional. If a hard direction moves a softer direction of another diamond, you might get a scratch. There is not much difference in this hardness, but a little goes a long way.

if the surface of a diamond never came in contact with another diamond can it still get scratches from everyday wear?..

Because a diamond is the hardest substance found in nature, it is sometimes misconceived as "unbreakable". It has four directions of cleavage, therefore if it receives a sharp blow in one of those directions it would split, or "cleave".

It would be very difficult to scratch during everyday wear, however, something with enough strength, applied with enough energy, at the "right" (but oh so wrong) angle could cause some damage.

 

[Dancing Fire]

would i be able to scrath the diamond with a metal file?

 

[denverappraiser]

would i be able to scrath the diamond with a metal file?

No. You could, however, chip it with a metal file so I wouldn't recommend using this as a test. It's tough on your file too.

 

[Jim Summa]

It would be very difficult to scratch during everyday wear, however, something with enough strength, applied with enough energy, at the "right" (but oh so wrong) angle could cause some damage.

I think this is a good description of what something (not always another diamond) can do to a stone resulting in chips or "percussion marks".
I never want to be complacent about the damage I can do to a stone. That being said I think diamonds are remarkably resistant to scratching.

 

[Dancing Fire]

would i be able to scrath the diamond with a metal file?

No. You could, however, chip it with a metal file so I wouldn't recommend using this as a test. It's tough on your file too.

Neil...i'd understand that a diamond CAN chip especially on the girdle,but what i don't understand is...can a diamond get scrathes w/o come in contact with another diamond?...

 

[Kaleigh]

If it hit something hard, I would venture to say yes. What happened DF???

 

[Kaleigh]

The hardness of diamond is directional. If a hard direction moves a softer direction of another diamond, you might get a scratch. There is not much difference in this hardness, but a little goes a long way.

if the surface of a diamond never came in contact with another diamond can it still get scratches from everyday wear?..

Because a diamond is the hardest substance found in nature, it is sometimes misconceived as "unbreakable". It has four directions of cleavage, therefore if it receives a sharp blow in one of those directions it would split, or "cleave".

It would be very difficult to scratch during everyday wear, however, something with enough strength, applied with enough energy, at the "right" (but oh so wrong) angle could cause some damage.

This is what I was thinking DF...

 

[Dancing Fire]

If it hit something hard, I would venture to say yes. What happened DF???

nothing,just wondering...

 

[yssie]

would i be able to scrath the diamond with a metal file?

No. You could, however, chip it with a metal file so I wouldn't recommend using this as a test. It's tough on your file too.

Neil...i'd understand that a diamond CAN chip especially on the girdle,but what i don't understand is...can a diamond get scrathes w/o come in contact with another diamond?...

Maybe if scratch is actually an accumulation of microchips along a single cleavage line..?
I too don't understand how hardness by scratching would have directionality as mentioned earlier, hopefully one of the experts can elaborate?

 

[Karl_K]

most scratches I have seen in diamonds are actually little chips or a series of chips.
Chipping diamonds is much much easier than scratching them.
Rub a diamond across a file and hit a facet junction and it will get chips on it unless your very lucky

 

[Luminous-MB]

most scratches I have seen in diamonds are actually little chips or a series of chips.
Chipping diamonds is much much easier than scratching them.
Rub a diamond across a file and hit a facet junction and it will get chips on it unless your very lucky

Right...