A couple of questions from a gemmology student

[Spear]

Hi guys,
I have recently started my first gemmology coarce(diamond essentials) with GIA
And I was wondering if I could ask you guys a couple of questions.

Some of these questions are things that I am struggling with in my coarce, but most of the questions are just things that I have been wondering about and that I would like to know for my own general knowledge.

The questions are as follows:

1. An Ideal cut is a diamond that returns all the light that enters the crown, while still displaying the maximum amount of fire.

The technology that allows us to see stars very far away with the Hubble telescope is based on the optical law: that when light reflects on a mirror at a certain angle, the light is magnified.

Do Ideal cuts work in the same way? In other words, does the light that reflect on the pavilion facets, reflect at such an angle that it is magnified?

That would imply that more light exits the stone, then what originally entered the stone or at least a higher intensity of light.

If this is not true of Ideal cuts, Can a diamond be cut in a way that it magnifies light in the same way as the mirrors in telescopes?

2. A colour or hue can fall under thousands of different shades.
The lightest shade of blue is white and the darkest shade is black.
So how do you know that a diamond that is graded D in colour, really is a D in the normal colour scale, and not just an extremely light shade of blue or red?

3. Do Laboratories consider laser inscription as clarity characteristic''s?

4. If all other factors are equal, What are more valuable, colourless diamonds or fancy yellow or brown diamonds?

5.What is Loupe clean and Eye clean?
In other words, what can be seen with the naked eye?

6. Diamonds that have symmetrically aligned facets, display hearts and arrows.
You can not see these hearts & arrows with the naked eye becuase the light that is reflected from the diamond is white.

Inside a hearts & arrows scope(if that is what you call it) is a sheet of coloured paper.
This paper turns the reflected light into coloured light.
If the light is blue for example, then you would be able to see the hearts & arrows.

What I would like to know is:
If I were to go into a room with a lamp thas has a blue light bulb and the only light-source in this room is this blue lamp, would I be able to see hearts & arrows in a diamond. (provided that the diamond''s facet''s are symmetrically aligned)

7. During the Second world war, diamonds were smuggled out of South Africa and into Germany.
These diamonds were used by the Nazi''s for the manufacture of weopons.

What I would like to know is: How are diamonds used for manufacturing weopons?
(I am not planning on making weopons, I am just curious about the purpose of diamonds in weopon manufacturing)



If anyone can help me answer these questions, It would be much appreciated.

Kind Regards
Kyran Barry (aka Spear)

 

[oldminer]

I have recently started my first gemmology coarce(diamond essentials) with GIA
And I was wondering if I could ask you guys a couple of questions.

Some of these questions are things that I am struggling with in my coarce, but most of the questions are just things that I have been wondering about and that I would like to know for my own general knowledge.

The questions are as follows:

1. An Ideal cut is a diamond that returns all the light that enters the crown, while still displaying the maximum amount of fire.

That''s a teaching definition, but don''t depend that maximimization fo colored light return, fire, is an essential of "Ideal".

The technology that allows us to see stars very far away with the Hubble telescope is based on the optical law: that when light reflects on a mirror at a certain angle, the light is magnified.

Do Ideal cuts work in the same way? In other words, does the light that reflect on the pavilion facets, reflect at such an angle that it is magnified?

Light is altered by a diamond and is intensified in some rewgions and diminished in others. There is no more light coming back than what went in, but it does now have hot spots.

That would imply that more light exits the stone, then what originally entered the stone or at least a higher intensity of light.

If this is not true of Ideal cuts, Can a diamond be cut in a way that it magnifies light in the same way as the mirrors in telescopes?

2. A colour or hue can fall under thousands of different shades.
The lightest shade of blue is white and the darkest shade is black.
So how do you know that a diamond that is graded D in colour, really is a D in the normal colour scale, and not just an extremely light shade of blue or red?

A very very very pale shade of any hue is white to our eyes and therefore at D color there is no hue, only tone.

3. Do Laboratories consider laser inscription as clarity characteristic''s?

Gitdle laser inscription is not an inclusion. SOme other areas of deposition or lasering might be considered a surface feature. I think every attempt so far has been regarded as no inclusion. Only a mistake creates a problem.

4. If all other factors are equal, What are more valuable, colourless diamonds or fancy yellow or brown diamonds?

Colorless are far more desired in volume. I suppose an unusually fine yellow may command a substantial premium over colorless. Brown diamonds are no contest.

5.What is Loupe clean and Eye clean?
In other words, what can be seen with the naked eye?

Loupe clean means an expert sees nothing with a hand held loupe. Eye Clean means an expert can barely see what he claims is totally invisible with the naked eye. A seller always has worse vision than a buyer.

6. Diamonds that have symmetrically aligned facets, display hearts and arrows.
You can not see these hearts & arrows with the naked eye becuase the light that is reflected from the diamond is white.
Inside a hearts & arrows scope(if that is what you call it) is a sheet of coloured paper.
This paper turns the reflected light into coloured light.
If the light is blue for example, then you would be able to see the hearts & arrows.
What I would like to know is:
If I were to go into a room with a lamp thas has a blue light bulb and the only light-source in this room is this blue lamp, would I be able to see hearts & arrows in a diamond. (provided that the diamond''s facet''s are symmetrically aligned)

No, you''d see a blue diamond. It is the contrast of white and colored light that is seen by engineering the way light enters the diamond in a H&A viewer.
7. During the Second world war, diamonds were smuggled out of South Africa and into Germany.
These diamonds were used by the Nazi''s for the manufacture of weopons.
What I would like to know is: How are diamonds used for manufacturing weopons?
(I am not planning on making weopons, I am just curious about the purpose of diamonds in weopon manufacturing)

I may be misinformed, but I''d assume the diamonds were converted to cash in a way similar to the Blood Diamonds from Africa of recent history. Unscrupulous dealers willing to sell out human lives for money probably made large profits and gave the German''s money with which to produce arms. Diamonds have a long history of being transportable wealth. For good or bad, that''s the way the world is.

 

[denverappraiser]

1. An Ideal cut is a diamond that returns all the light that enters the crown, while still displaying the maximum amount of fire.
‘Ideal’ is a term used to describe a specific set of parameters. It’s not used the same way by everyone. I’ve never seen a definition where 100% light return is the rule.
The technology that allows us to see stars very far away with the Hubble telescope is based on the optical law: that when light reflects on a mirror at a certain angle, the light is magnified.

The mirror in a telescope magnifies because it’s curved in the form of a parabola and therefore has a focusing effect on the light. Diamonds do not generally have the same effect.

That would imply that more light exits the stone, then what originally entered the stone or at least a higher intensity of light.

Physics doesn’t work that way. You only get out what comes in, maybe less.

If I were to go into a room with a lamp thas has a blue light bulb and the only light-source in this room is this blue lamp, would I be able to see hearts & arrows in a diamond. (provided that the diamond''s facet''s are symmetrically aligned)

Look into your H&A viewer from the bottom. Notice the white plate at the end of the colored cylinder with the eyehole in it. The reflection of this plate and the contrast with the colored walls is what causes the image.

What I would like to know is: How are diamonds used for manufacturing weopons?
(I am not planning on making weopons, I am just curious about the purpose of diamonds in weopon manufacturing)

Diamonds were used as bearings in precision machinery like bomb sights and other targeting equipment. They were also used in tooling for manufacturing of various things that required precision cutting.

Neil Beaty
GG(GIA) ISA NAJA
Independent Appraisals in Denver

 

[Spear]

I just want to thank the two of you for taking the time to answer all of my questions.
Its good to learn something new every day!

Sincerely
Kyran Barry

 

[RockDoc]

Dave and Neil have written very good answers to your questions, however you also need to consider where the light is being returned the most. Some diamonds return light very uniformly, others do not.

The H&A viewer is only one useful technology. There are other instruments that are available : These include

1. Firescope, ASET scope,Ideal Scope

2. Isee2, ImaGem, Brilliance Scope

In some stone the H&A image is more pronounced than others.

In some lighting environments the images may be visible without using an H&A viewer, and the type of viewer used can vary the image as well.

Congratulations on taking the first step ( your 1st GIA course ) as this is more than many people do.

Rockdoc

 

[Spear]

I found the answer to my own question.
lol

We found US intelligence reports on an extraordinary secret joint British-American investigation into how Hitler''s Germany obtained the diamonds essential for cutting the steel, making ball bearings and drawing the wire needed for its weapons. The investigation, completed in 1944, found Germany was being supplied with these vital diamonds from the Congo and that this trade with Germany was protected by people in key positions in a British Government Ministry.

 

[strmrdr]

DeBeers also refused to sell the US a large supply of diamonds to keep in the US for the same use.
Luckily some alternatives were found but not before it cost some lives due to lack of meterial or inferier materials having to be used.