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Author Topic: Only a diamond can cut glass.  (Read 23298 times)

paul.fr

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Only a diamond can cut glass.
« on: 18/08/2007 21:56:09 »
I remember reading that only a genuine diamond can cut or scratch glass, is this true? Should i check my girlfriends ring?


NB: I dont have a girlfriend (offers taken) or a diamond ring, just a question  :(

neilep

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Only a diamond can cut glass.
« Reply #1 on: 18/08/2007 22:07:23 »
Sorry, did you say you wanna buy a ring ?

neilep

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Only a diamond can cut glass.
« Reply #2 on: 19/08/2007 00:53:08 »
Ok, I am fairly sure that a diamond is not prerequisite to cut glass.

I am sure that very hard steel will do the job just as well.

It may be that only a diamond can cut or cleave a diamond though...well..a diamond tipped cleave !.....but then...now that I think about it.....that also may not be the case as you generally would cleave a diamond along a natural fracture...and so would not need to have a diamond tipped cleave.

Still, as far as the original question is concerned..........no...........hardened steel will do the job.....I've seen it done a few times.

Scribe a channel then split it !!

Karen W.

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Only a diamond can cut glass.
« Reply #3 on: 19/08/2007 01:11:22 »
Ok, I am fairly sure that a diamond is not prerequisite to cut glass.

I am sure that very hard steel will do the job just as well.

It may be that only a diamond can cut or cleave a diamond though...well..a diamond tipped cleave !.....but then...now that I think about it.....that also may not be the case as you generally would cleave a diamond along a natural fracture...and so would not need to have a diamond tipped cleave.

Still, as far as the original question is concerned..........no...........hardened steel will do the job.....I've seen it done a few times.

Scribe a channel then split it !!

I didn't know that I was always told that diamond was the only thing that cuts glass. Thats what the glass man in Mckinleyville told me they have to use in there equiptment while cutting their glass. Maybe it is just common and not must do thing.. Huh!

Buy The way I just bought a new ring go look in diary need to know something more about the stones!!!

JimBob

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Only a diamond can cut glass.
« Reply #4 on: 19/08/2007 03:05:41 »
There is something called the Mohs hardness scale. It is a list of minerals in a ralative sense of hardness

The list is as follows

Hardness   Substance or Mineral

1          Talc
2          Gypsum
2.5 to 3      pure Gold, Silver
3             Calcite, Copper penny
4          Fluorite
4 to 4.5      Platinum
4 to 5          Iron
5          Apatite
6          Orthoclase
6          Titanium
6.5          Iron pyrite
6 to 7          Glass, Vitreous pure silica
7          Quartz (Crystallized silica)
7 to 7.5      Garnet
7 to 8          Hardened steel
8          Topaz
9          Corundum
10          Diamond
>10          Aggregated diamond nanorods

Anything from 7 up can cut glass

There is a little ambiguity in that the minerals listed are the ones used to define the scale. Others can be used interchangeably. One, corundum, for instance, is a ruby if it is red, a sapphire if it is blue.

There are other details we of the Illuminati know about this subject but are loath to share with the huddled masses.

So There, Karen - (big raspberry)

neilep

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Only a diamond can cut glass.
« Reply #5 on: 19/08/2007 03:12:51 »
 I don't wish to disagree with the Uber Jim Bob but I thought that the Mohs scale is not a scale of relative hardness but just a scale of what is hard displayed in scale form.

ie: I think the gap between the hardness of a diamond and a corundum is far far more than the gap between the hardness difference between a corundum and Topaz !..and so on and so forth !!
« Last Edit: 19/08/2007 13:01:18 by neilep »

Karen W.

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Only a diamond can cut glass.
« Reply #6 on: 19/08/2007 03:49:53 »
I don't wish to disagree with the Uber Jim Bob but I thought that the Mohs scale is not a scale of relative hardness but just a scale of what is hard displayed is scale form.

ie: I think the gap between the hardness of a diamond and a corundum is far far more than the gap between the hardness difference between a corundum and Topaz !..and so on and so forth !!
There is something called the Mohs hardness scale. It is a list of minerals in a ralative sense of hardness

The list is as follows

Hardness   Substance or Mineral

1          Talc
2          Gypsum
2.5 to 3      pure Gold, Silver
3             Calcite, Copper penny
4          Fluorite
4 to 4.5      Platinum
4 to 5          Iron
5          Apatite
6          Orthoclase
6          Titanium
6.5          Iron pyrite
6 to 7          Glass, Vitreous pure silica
7          Quartz (Crystallized silica)
7 to 7.5      Garnet
7 to 8          Hardened steel
8          Topaz
9          Corundum
10          Diamond
>10          Aggregated diamond nanorods

Anything from 7 up can cut glass

There is a little ambiguity in that the minerals listed are the ones used to define the scale. Others can be used interchangeably. One, corundum, for instance, is a ruby if it is red, a sapphire if it is blue.

There are other details we of the Illuminati know about this subject but are loath to share with the huddled masses.

So There, Karen - (big raspberry)

HEE HEE HE.. LOL tHat means My glass man is full of POO!.. LOL It also means You have done a great job on EWER Homework! LOL YAYYYYYYYYYY! Accepts the bloody Rasberry and sends you ONE BACK except I cant find my smily Rasberry! LOL! I think he had sound too!

Seriously that is very cool. You don't know how many years us kids tried to cut wholes through our bedroom window with my moms diamond rings! LOL LOL! scratch the crud out of the windows but no escape window worked! LOL... SHUCKS!!!! THUUUUUUUUUUUBBBBBBBBBBB!!!  I am so Proud.... LOL See the boy did his homework!

paul.fr

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Only a diamond can cut glass.
« Reply #7 on: 19/08/2007 06:52:20 »
Thanks for the answers, i think i worded this wrongly (i know, shocking). I meant stones, can other stones cut glass.

thanks and sorry for passing on my confusion

frethack

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Only a diamond can cut glass.
« Reply #8 on: 19/08/2007 09:28:43 »
Quote
I don't wish to disagree with the Uber Jim Bob but I thought that the Mohs scale is not a scale of relative hardness but just a scale of what is hard displayed is scale form.

Mohs is a scale used for relative hardness but not absolute hardness.  This is the same way that relative dating tells you that the Cambrian came before the Silurian, but absolute dating would tell you that they occured about 45 million years apart.  I think JimBob is giving examples of minerals that can cut glass, without regard to the mineral that is most efficient. Generally, anything with a relative hardness above 6 will at least scratch your standard piece of glass (did it all last semester...ugh  xx( )

An absolute hardness scale would look something like this:

Hardness / Mineral
_______________________
         
1          Talc
3          Gypsum
9          Calcite
21         Fluorite
48         Apatite
72         Orthoclase
100        Quartz
200        Topaz
400        Corundum
1600       Diamond




neilep

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« Reply #9 on: 19/08/2007 13:12:04 »
There is always the Brinell scale:

3 talc
12 Gypsum
53 Calcite
64 Fluospar
137 Apatite
147 Feldspar
178 Quartz
304 Topaz
667 Conundrum
--- Diamond......

Hmmm..don't know why there's no number for diamond !


JimBob

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Only a diamond can cut glass.
« Reply #10 on: 19/08/2007 19:44:11 »
Welcome frethack, Hope your a geologer - we need more here.

To the rest of you,
As I said above "here are other details we of the Illuminati know about this subject but are loath to share with the huddled masses."



frethack

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Only a diamond can cut glass.
« Reply #11 on: 20/08/2007 08:10:39 »
Why thank you, JimBob...I am but one of the huddled masses, working his tail off to be educated in the arts of the Illuminati. 


paul.fr

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Only a diamond can cut glass.
« Reply #12 on: 20/08/2007 08:24:24 »
Hi fretack,

Are you saying that those diamond lookalikes "cubic zirconia " will also cut glass? Does this mean that someone could be wearing a ring made of cubic zirconia, scratching glass and not knowing that an unscrupulous jeweler has just sold them a "fake"?

eric l

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Only a diamond can cut glass.
« Reply #13 on: 20/08/2007 09:07:30 »
AFIK juwelers do not use scratching properties (=hardness) to see the difference between cubic zirconia (or "zircon" as they call it) and diamond, but density.  They use a special balance and determine weight and "under water weight".
 

paul.fr

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Only a diamond can cut glass.
« Reply #14 on: 20/08/2007 09:11:36 »
AFIK juwelers do not use scratching properties (=hardness) to see the difference between cubic zirconia (or "zircon" as they call it) and diamond, but density.  They use a special balance and determine weight and "under water weight".
 

Eric, perhaps i am having another bad construction day.

I meant. if one believed that only a diamond could cut cut glass, when infact a zircon would also. Could you be walikng around wth a zircon that you bought as a diamond?
This is assuming that a zircon is hard enough to cut glass, again that is my poorly constructed question - is the zircon hard enough?

eric l

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Only a diamond can cut glass.
« Reply #15 on: 20/08/2007 09:48:18 »
This is assuming that a zircon is hard enough to cut glass, again that is my poorly constructed question - is the zircon hard enough?

AFIK :  yes it is.  Of course, this weighing method can only be used on the stone, not on the stone in a setting.  There may be a kind of hardened steel plate that is scratched by a diamond and not by a zircon, but I can not be positive on that.

frethack

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Only a diamond can cut glass.
« Reply #16 on: 20/08/2007 19:02:55 »
Quote
Hi fretack,

Are you saying that those diamond lookalikes "cubic zirconia " will also cut glass? Does this mean that someone could be wearing a ring made of cubic zirconia, scratching glass and not knowing that an unscrupulous jeweler has just sold them a "fake"?

Unfortunately yes.  Even quartz will scratch glass, though they are essentially the same material (silicates) with a different crystal structure.

neilep

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« Reply #17 on: 20/08/2007 19:20:37 »
Even glass will scratch glass.......i think !!

paul...only purchase diamonds from reputable suppliers ! ;)

JimBob

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« Reply #18 on: 20/08/2007 20:02:11 »
Why thank you, JimBob...I am but one of the huddled masses, working his tail off to be educated in the arts of the Illuminati. 




You have come to the right place, my son.

Dominos, dominos, vo bist dem dominos. Amen

Bored chemist

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« Reply #19 on: 20/08/2007 21:03:27 »
Well, a diamond is hard enough to scratch sapphire but zirconia isn't. Since synthetic sapphire is quite cheap you could use it as a test, but the density is a better way to check. Of course it's rather difficult if the stone is set in a ring or something.
I have heard that one way to tell zirconia from diamond is that diamond, being a much better conductor of heat, feels cold if you put it against your lip. I don't think I'd like to have to bet on this technique.

eric l

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« Reply #20 on: 21/08/2007 07:53:45 »
I have heard that one way to tell zirconia from diamond is that diamond, being a much better conductor of heat, feels cold if you put it against your lip. I don't think I'd like to have to bet on this technique.
A distant cousin of mine is a watchmaker (well, repairer actually) and jeweler.  He puts the tip of his tongue to it.  But since he does the same thing when assessing gold, it may be just a gimmick to impress customers.  And he does combine this "tips of the tongue feeling" with other tests.

 

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