Teach Me!

[lulu_ma]

Yes and NO! Depending on cut quality - the shorter the ray paths through a diamond the less color will be seem face up.
Perfect rounds have very short ray paths, averaging around 2.5 time diameter.
Diamonds cut to increase color have three time avg ray path lengths.
Most fancy shapes have poor light return and so they show lower colors.
The round and cushion shown are digital and have identical material color!

I’m going to piggy back off SH’s question-why did so many old cut diamonds have face ups whiter than grade?

I’d love to know the science behind this phenomena.

 

[Garry H (Cut Nut)]

I’m going to piggy back off SH’s question-why did so many old cut diamonds have face ups whiter than grade?

I’d love to know the science behind this phenomena.

Did you see my post before yours?
That is why - less than perfect light return.

 

[lulu_ma]

Did you see my post before yours?
That is why - less than perfect light return.

I'll admit that I am confused. Super Ideal diamonds seem to face up whiter due to excellent light return. Conversely, OECs and OMCs face up whiter due to poor light return and/or short ray paths?

 

[Garry H (Cut Nut)]

I'll admit that I am confused. Super Ideal diamonds seem to face up whiter due to excellent light return. Conversely, OECs and OMCs face up whiter due to poor light return and/or short ray paths?

Sorry - I misread your post.
Old cuts that face up whiter are often from South Africa - the cape yellowish - many of which are blue fluorescent. That improves the colour you see in good lighting.
But the issue is complex. The models in this image are the same diameter and color absorption because they are virtual software modeled diamonds.

 

[lulu_ma]

Thanks for the info.

Interestingly, I was recently at Shimansky in Cape Town and tried on these two. The round is a GIA M color with faint fluoro. The oval is a IGI J color.

In person the face up color looked quite similar:

 

[Karl_K]

Smaller tables and no lower girdle facets under the table means there are fewer small virtual facets that concentrate color.
Less of a difference than crushed ice to rb but it is there.

 

[snaphappy]

Thanks for the info.

Interestingly, I was recently at Shimansky in Cape Town and tried on these two. The round is a GIA M color with faint fluoro. The oval is a IGI J color.

In person the face up color looked quite similar:

I think that's why they were just called cape diamonds in the old days. They're all quite similar to the naked eye.

Cape Town? Wow!! Have you been to the museum, is it in Kimberly? I'd kill to see the Eureka Diamond!!

 

[Garry H (Cut Nut)]

Thanks for the info.

Interestingly, I was recently at Shimansky in Cape Town and tried on these two. The round is a GIA M color with faint fluoro. The oval is a IGI J color.

In person the face up color looked quite similar:

IGI tends to be softer on colour so the difference should be slight anyway. But to see colours diffused light works best

 

[lulu_ma]

I think that's why they were just called cape diamonds in the old days. They're all quite similar to the naked eye.

Cape Town? Wow!! Have you been to the museum, is it in Kimberly? I'd kill to see the Eureka Diamond!!

I did go to the Diamond Museum in Cape Town. Unfortunately, the Kimberly mine was a 12 hour drive so I did not see the famed diamond!

 

[snaphappy]

Easy to answer questions:

When I'm seeing chunkier flashes of light from an OEC, are those flashes derived from pavilion facets/lower girdle facets?

I ask because... from the top, the facets on my "OEC" look the same as my wife's "round." I think both are transitional cuts that pre-date WWII

 

[Garry H (Cut Nut)]

Easy to answer questions:

When I'm seeing chunkier flashes of light from an OEC, are those flashes derived from pavilion facets/lower girdle facets?

I ask because... from the top, the facets on my "OEC" look the same as my wife's "round." I think both are transitional cuts that pre-date WWII

That will be the mains Snappy.

 

[snaphappy]

My wife asked me today "would a new modern round brilliant look less dark in direct sunlight than our old diamonds?"

I told her no. But then I told her I'd ask you guys to make sure.

I must admit, Gary has me curious about finding a shallow round brilliant to see what all the fuss is about!

But all rounds are going to look dark in direct sunlight if they're well cut, right?

 

[Garry H (Cut Nut)]

My wife asked me today "would a new modern round brilliant look less dark in direct sunlight than our old diamonds?"

I told her no. But then I told her I'd ask you guys to make sure.

I must admit, Gary has me curious about finding a shallow round brilliant to see what all the fuss is about!

But all rounds are going to look dark in direct sunlight if they're well cut, right?

Wrong. The better the cut the worse the darkness.
Later I will show some evidence.

 

[snaphappy]

Wrong. The better the cut the worse the darkness.
Later I will show some evidence.

No you don't need to go to all that trouble. I have your book and I'm about to re-read it. I read it very quickly the first time on the kindle and I didn't retain a lot of the info.

I think my wife was just expressing fear our old diamonds might not be as pretty as new diamonds.

So potentially, our old diamonds are less dark in direct sunlight because they're not cut as well as new RBC's! She'd actually like that.

I'm still planning on finding someone local that will show me RBC's because I've never seen one in person.

 

[Garry H (Cut Nut)]

No you don't need to go to all that trouble. I have your book and I'm about to re-read it. I read it very quickly the first time on the kindle and I didn't retain a lot of the info.

I think my wife was just expressing fear our old diamonds might not be as pretty as new diamonds.

So potentially, our old diamonds are less dark in direct sunlight because they're not cut as well as new RBC's! She'd actually like that.

I'm still planning on finding someone local that will show me RBC's because I've never seen one in person.

Here you go for those that don't have my book and might be learning

Some good diamonds look dark in sunlight

Some good white diamonds look dark in direct sunlight. Yellow diamonds look great in sunlight but white diamonds look best in shaded lighting.

www.hollowaydiamonds.com.au

 

[Texas Leaguer]

I wouldn't predicate my opinion on the beauty of a diamond based on how it looks in direct sunlight unless you are a lifeguard . Strong directional light will accentuate contrast and make diamonds go over-dark in general. So it is really not the most flattering light for any diamond, although you can sometimes get fabulous sparks of fire (colored sparkles) in direct sun when viewed from some distance.

Sunlight on a cloudy day, however, will make the diamond look completely different! The clouds diffuse the light helping it to fill in the diamond, allowing you to see the overall brightness of the stone. The downside of this is that fire is suppressed.

The best of both world is the example Garry uses frequently of observing the stone under a leafy tree in direct sun. Those myriad pinpoint light sources between the leaves can make a well cut diamond very happy!

 

[snaphappy]

I'm just going to ask here, instead of making a new post...

I'm semi-retired. Not rich. But I have enough money where I can pursue hobbies very intensely. And frankly I'm really bored in an empty house.

I'm curious about GIA (or other types) of gem education. Is GIA education like a bachelors degree? Or is it appropriate for a hobbyist? What you would recommend? Or should I just stay out of it and keeping reading books?

 

[Texas Leaguer]

I'm just going to ask here, instead of making a new post...

I'm semi-retired. Not rich. But I have enough money where I can pursue hobbies very intensely. And frankly I'm really bored in an empty house.

I'm curious about GIA (or other types) of gem education. Is GIA education like a bachelors degree? Or is it appropriate for a hobbyist? What you would recommend? Or should I just stay out of it and keeping reading books?

I would say that the formal GIA pathway is structured for people in the business or who want to go into the business. But I know of some who did the whole course just because they found it fascinating. That said, you can learn a tremendous amount on your own in a more self-directed way (and at less cost!). This will allow you to follow your particular areas of interest, such as cut quality.

GIA has an overview course called the Accredited Jewelry Professional which is basically an introduction to the areas of focus of the GIA graduate gemology program. It's pretty easy to complete in a short time and it gives you a sampling to help you decide what other courses you might want to take, and/or whether you want to plunge into the GG program.

GIA also publishes their research studies, so you can study those if you really want to get into the weeds!

 

[snaphappy]

I would say that the formal GIA pathway is structured for people in the business or who want to go into the business. But I know of some who did the whole course just because they found it fascinating. That said, you can learn a tremendous amount on your own in a more self-directed way (and at less cost!). This will allow you to follow your particular areas of interest, such as cut quality.

GIA has an overview course called the Accredited Jewelry Professional which is basically an introduction to the areas of focus of the GIA graduate gemology program. It's pretty easy to complete in a short time and it gives you a sampling to help you decide what other courses you might want to take, and/or whether you want to plunge into the GG program.

GIA also publishes their research studies, so you can study those if you really want to get into the weeds!

If I started a new career through their course work, what would I do? Appraise? Grade? Can I work from home? Would I work at a local jewelry store? is it 9-5?

I really don't know anything about how it all works. Maybe I'll check the GIA's youtube page and see if they have an overview

 

[Garry H (Cut Nut)]

I wouldn't predicate my opinion on the beauty of a diamond based on how it looks in direct sunlight unless you are a lifeguard . Strong directional light will accentuate contrast and make diamonds go over-dark in general. So it is really not the most flattering light for any diamond, although you can sometimes get fabulous sparks of fire (colored sparkles) in direct sun when viewed from some distance.

Sunlight on a cloudy day, however, will make the diamond look completely different! The clouds diffuse the light helping it to fill in the diamond, allowing you to see the overall brightness of the stone. The downside of this is that fire is suppressed.

The best of both world is the example Garry uses frequently of observing the stone under a leafy tree in direct sun. Those myriad pinpoint light sources between the leaves can make a well cut diamond very happy!

The leafy tree actually works best on a bright but cloudy day!

 

[Garry H (Cut Nut)]

I'm just going to ask here, instead of making a new post...

I'm semi-retired. Not rich. But I have enough money where I can pursue hobbies very intensely. And frankly I'm really bored in an empty house.

I'm curious about GIA (or other types) of gem education. Is GIA education like a bachelors degree? Or is it appropriate for a hobbyist? What you would recommend? Or should I just stay out of it and keeping reading books?

Sounds like you would be far better off with the British FGAA course that is more technically and scientifically focused.
The GIA courses teach you enough to know how to pay them money for their services.

 

[Texas Leaguer]

If I started a new career through their course work, what would I do? Appraise? Grade? Can I work from home? Would I work at a local jewelry store? is it 9-5?

I really don't know anything about how it all works. Maybe I'll check the GIA's youtube page and see if they have an overview

There is a pretty active network of GIA alum associations. There may be one in your area. They meet once in a while for networking and sometimes have a speaker. Connecting with some of those folks might help you figure out what area of the business might be a good fit. GIA also has career resources you might tap into.

Jewelry stores are always looking to hire around the holidays. Some experience behind the counter is really helpful no matter what you ultimately do.

 

[snaphappy]

Gary I'm watching a presentation by GCAL on youtube. They seem to be very focused on cut. Do you like these guys? Are they your preferred American lab?

 

[Garry H (Cut Nut)]

Gary I'm watching a presentation by GCAL on youtube. They seem to be very focused on cut. Do you like these guys? Are they your preferred American lab?

Not entirely. Lots of pluses and a few negatives - but inappropriate for me to state the negatives publicly.

 

[snaphappy]

Why don't labs unset/set diamonds and appraise? And while the diamond is out, maybe improve the polish if need be. That may sound silly, but I live in a dangerous city. I don't want a local jeweler removing my diamond and sending it to GIA. I'd rather just send my ring to GIA directly because they're trustworthy. And for the life of me, why doesn't every lab appraise?

Think about this: I have to take a $20k ring into a violent, dangerous city. Drop it off with a drug dealer/jeweler with hundreds of negative reviews. That awful jeweler is going to remove my diamond, potentially damage all kinds of things, then send it to GIA. When the diamond comes back, the oft arrested jeweler has to put the diamond back in the ring and send the ring off to be appraised. Even if you live in a wonderful, crime free community, sending your jewelry to multiple places like this a nuisance.

An all-in-one experience would be superior and potentially more profitable

 

[Garry H (Cut Nut)]

Why don't labs unset/set diamonds and appraise? And while the diamond is out, maybe improve the polish if need be. That may sound silly, but I live in a dangerous city. I don't want a local jeweler removing my diamond and sending it to GIA. I'd rather just send my ring to GIA directly because they're trustworthy. And for the life of me, why doesn't every lab appraise?

Think about this: I have to take a $20k ring into a violent, dangerous city. Drop it off with a drug dealer/jeweler with hundreds of negative reviews. That awful jeweler is going to remove my diamond, potentially damage all kinds of things, then send it to GIA. When the diamond comes back, the oft arrested jeweler has to put the diamond back in the ring and send the ring off to be appraised. Even if you live in a wonderful, crime free community, sending your jewelry to multiple places like this a nuisance.

An all-in-one experience would be superior and potentially more profitable

(Thread jackish - but preachy education coming)
You trust a beuacracy more than a person you can eye ball?
Find an established good bench jeweler.
Most will be mortally offended if you ask to be present.
But you can try.
Or find an appraiser who will manage the process from go to wo.