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Jewelry store lighting

kah42

Shiny_Rock
Joined
Aug 17, 2018
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We all know that jewelry stores use lighting to help make even the worst cut diamonds look sparkly and bright. But is there a way to shield the lighting or otherwise evaluate how the stone will perform before looking at the certificate? I presume it would help to look at diamonds near a window, but are there any other things to try to help eliminate poor performers?

Basically I'm wondering if there is a way to save time evaluating certificates for clearly poor cuts by just viewing a diamond, and focus on certificates/ASETs/etc. for stones that might be worth it.
 
I would also be interested in this. One of the things I tried to look into was if there was a handheld device that was able to simulate different kinds of lighting. Unfortunately, I wasn’t able to find anything. Maybe someone here might have some ideas?
 
I would also be interested in this. One of the things I tried to look into was if there was a handheld device that was able to simulate different kinds of lighting. Unfortunately, I wasn’t able to find anything. Maybe someone here might have some ideas?

You can purchase an ASET or Ideal Scope. Both are handheld and easy to use. Between these two I would recommend getting the ASET. Certs are also useful to quickly eliminate stones if you know what to look for. If the diamonds are in front of you, the ASET or Ideal Scope is what you would want to use to confirm light performance.

For round diamond specs use the following as a guide:

Table: 54-57
Depth: 60-62.4
CA: 34-35
PA: 40.6-41
Girdle: thin to medium, thin to slightly thick; avoid extremes like very thin, thick, very thick

CA and PA should complement one another. 34 CA with a 41 PA and a 35 CA with a 40.6 PA.
 
Please see my profile photo.
You can just roll any paper to create a ghetto IS/ASET. You don't need to use all three colors. Just use red. Or use white.

If you got nothing, rub your hands and fingers to make them red. Make the small OK sign. Now, you basically have a red cylinder that can be used as a ghetto idealscope. Use the jewelry display case as your back light. If done right, you can assess the arrows and light leakage, and even girdle treatment (painting/digging) as long as the diamond is a decent size (6.00mm+), without any magnification.

Or get a real idealscope or ASET scope.
 
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A few years ago I was outside a small jewellers waiting for it to open and the owner unlocked the door, we walked in and he said 'I'll just switch the magic lights on' as he prepared the shop for trade.
 
Put it under the counter - away from the ceiling lights. Just tell the sales associate you are going to do that — before you do that.
 
Ringo gives part of the advice I was going to offer. The rest is to cup your hand high enough above the diamond to cast the diamond in shadow, but not so close that all you see is massive obstruction.

I posted these in another thread yesterday, but when I show this set of stones in jewelry store lighting they look great.

diamond-brightness-size-1.jpg

Put my hand over them and this is what you get...

diamond-brightness-size-2.jpg

Wink
 
The job of jewelry stores is to make their stuff look good so it's not like this is an evil plot. The first step is to tell the salesperson your concerns and see what other lighting environments. Normally, for example, there are rather bright lights directly over the showcases and a relatively dark area in the middle of the room. The store usually has several different sorts of lighting environments and the staff will know where they are.
 
Put it under the counter - away from the ceiling lights. Just tell the sales associate you are going to do that — before you do that.
I do this all the time. I tell them I am taking it under the counter and then I squat down and put it under where there is a lot less light. I take it to the darkest corner of the room. A good performer will still sparkle. A poor one will not.
 
I will probably do and post DIY IS Part 3.
 
A bit of paper makes for a nice light block, but try to not block the salesperson view of the diamond, it makes them nervous.
 
Here is what you should expect. It is not the best photo, as I had to hold and make the OK sign with one hand and take the photo with the other hand.

As you can see the diamond is mostly pinkish, which is the color of my skin. It is pinkish enough to see the white leakage under the table at 12 o'clock and 11 o'clock. The arrows are black, which is the reflection of my camera case. If you are not taking a photo, the arrows will look silvery. The silvery arrow at 1 o'clock is the reflection of the camera lense.

20181016_202410.jpg
 
Reminds me of a bit of a story I used the paper trick and the jeweler shakes his head and says I spent 15k on lights so you could enjoy the diamond in awesome lighting and you block it out!
I laughed.
 
Reminds me of a bit of a story I used the paper trick and the jeweler shakes his head and says I spent 15k on lights so you could enjoy the diamond in awesome lighting and you block it out!
I laughed.
I do not like using paper or ASET/IS at a store, unless I am serious about buying a diamond.
Many jewellers become defensive and tell me "oh.. you saw that ONLINE?" with sarcasm.
When I just hang out at Tiffany or Cartier, this hand trick is low-profile and good enough.
 
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I do not like using paper or ASET/IS at a store, unless I am serious about buying a diamond.
Many jewellers become defensive and tell me "oh.. you saw that ONLINE?" with sarcasm.
When I just hang out at Tiffany or Cartier, this hand trick is low-profile and good enough.

Good advice. I would not bring my IS with me unless I was very serious about buying a particular diamond. The cupping the hand trick recommended by @flyingpig is good enough to get a general idea of the diamond's cut.

FYI I would also not bring it under the counter. That can look pretty shifty to jewelers (like you're going to try and swap it) and might make them nervous.

Better is to ask them if there is a dimly-lit area of the store to take the diamond, or ask them if you can take it outside (with the SA with you, of course) to look at the diamond in indirect sunlight (under a tree works well).
 
Ringo gives part of the advice I was going to offer. The rest is to cup your hand high enough above the diamond to cast the diamond in shadow, but not so close that all you see is massive obstruction.

I posted these in another thread yesterday, but when I show this set of stones in jewelry store lighting they look great.

diamond-brightness-size-1.jpg

Put my hand over them and this is what you get...

diamond-brightness-size-2.jpg

Wink

That's a great pair of photos :) They seem to show what @Garry H (Cut Nut) is attempting to add to the HCA tool, I think??
 
It is not the best photo, as I had to hold and make the OK sign with one hand and take the photo with the other hand.

When I was at GIA as a student back in the dark ages, one of my instructors, I do not remember if it was Ray Page or Mike Albrighton, taught me to cup my hand around a diamond and look at the table reflection in the culet area to judge the table size without using a loupe. (There were no arrows, or hearts, back then and most diamonds still had culets.)

The more things change, the more some of them stay the same. The technique still works, although we may be using it for a completely different view and purpose. Back then, the diamond with a report was relatively rare, now they are required for an Internet retailer and for the better quality stores.

I often wonder what things will be like in another twenty years of this rapidly changing landscape of tools and knowledge.

Wink
 
Sometimes I get the SA to hold a piece of paper or tray over the diamond so that I can see it properly.

Depending on the store, some may even switch off the spot lights if you ask...
 
When looking for my ER in the 1980s I could not decide between oval or emerald cut. Went to a jewelers in the Pittsfield Bldg high above Wabash St (jewelers row) in Chicago where my mom bought her ER in the 1950s and other jewelry and my sister got her ER. I said I was interested in 3 carats high color and quality for a traditional three stone (baguette) plat ring. I was escorted to a back room to view stones. The sales lady showed me a 3 carat EC that was a E-F and high Vs. A really pretty stone stat wise and had nice flash. I asked to see it by the window and under flourescent light. The saleslady asked why would I want to look at the stone under these conditions. Now I am a bit ticked off because the answer is obvious and she is questioning my knowledge. I politely told her that I work in an office with fluor lights-not showroom lights and I wanted to see how the stone performed under less optimal light. I took it over to the window and boy was that one crappy ice cube. It was dead. She asked if I was interested and I said no because the stone was cut to save weight. She was a bit floored at my response and asked if I wanted to see other stones. I said no, thanked her for her time and never returned. Looking at my sister's stone, the cut is way too deep and it is a dead 2 carat. My mom's stone was beautiful, however. Lesson learned, if they won't show you what you want to see in a different light then leave. Ask to see the stone in a back office (there is one) that has the correct lighting that they use to view stones.
 
Ringo gives part of the advice I was going to offer. The rest is to cup your hand high enough above the diamond to cast the diamond in shadow, but not so close that all you see is massive obstruction.

I posted these in another thread yesterday, but when I show this set of stones in jewelry store lighting they look great.

diamond-brightness-size-1.jpg

Put my hand over them and this is what you get...

diamond-brightness-size-2.jpg

Wink

@Wink wow this is great! Sorry for this newb question, but this shows basically that the 0.8 left image has significant light leakage, whereas the 1.0 right image has moderate light leakage under the table?
 
@Wink wow this is great! Sorry for this newb question, but this shows basically that the 0.8 left image has significant light leakage, whereas the 1.0 right image has moderate light leakage under the table?
The dark areas are light leakage (the black surface behind showing through).

The light areas are light return (hence are bright).

The 0.8 therefore has better light return than the 1.0 - and because the 1.0 leaks around the edges, the bright area is only as large as a well-cut 0.8.

I believe I'm correct in saying that Wink's underlying point is that one is better to purchase a well-cut 0.8 than a poorly-cut 1.0, because the piece of paper stating the weight is not what you wear on your finger, the diamond is - and if a 0.8 looks as big as a 1.0, why waste the extra money?
 
The dark areas are light leakage (the black surface behind showing through).

The light areas are light return (hence are bright).

The 0.8 therefore has better light return than the 1.0 - and because the 1.0 leaks around the edges, the bright area is only as large as a well-cut 0.8.

I believe I'm correct in saying that Wink's underlying point is that one is better to purchase a well-cut 0.8 than a poorly-cut 1.0, because the piece of paper stating the weight is not what you wear on your finger, the diamond is - and if a 0.8 looks as big as a 1.0, why waste the extra money?
Actually it has less to do with leakage and more to do with where it is drawing light.
Garry can you post ASET images for the 2 stones?
 
Actually it has less to do with leakage and more to do with where it is drawing light.
Garry can you post ASET image for the 2 stones?
Ah yes, I see where you're coming from :)

(Although I think you mean @Wink! lol)
 
Maybe you can hire one of these geniuses to go diamond shopping with you? Don't forget your ear plugs. :lol:


 
Ah yes, I see where you're coming from :)

(Although I think you mean @Wink! lol)
*grin*
Garry has the sets CZs custom cut and sells them. Wink got them from Garry.
I at one time considered the CZs a bit of a parlor trick because they are cut to exaggerate the problem.
When I had access to to the rap list I did some looking and stones this bad are out there.
So I now consider it a fair if somewhat exaggerated teaching tool.
 
*grin*
Garry has the sets CZs custom cut and sells them. Wink got them from Garry.
I at one time considered the CZs a bit of a parlor trick because they are cut to exaggerate the problem.
When I had access to to the rap list I did some looking and stones this bad are out there.
So I now consider it a fair if somewhat exaggerated teaching tool.
As requested Karl, plus a new addition - the 'Average' equivalent that many people experience in Maul stores.View attachment 654487
 
Here is an an enlargement of the bad cz image.
Notice the upper girdle facets between the arrows.
They are not white with leakage, they are greenish grey, this is from being way to steep and not drawing light hardly at all from a useful direction.
The upper girdle facet angles relationship determines edge to edge brightness in a similar way lower girdles control under table leakage.
Bright lighting covers this to some extent hence the demo works.

https://www.pricescope.com/articles/do_pavilion_mains_drive_light_return_modern_round_brilliant

badimage.jpg
 
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