A bunch of general questions about diamonds

[GemFever]

Dear PSers,

As I play with my little collection of diamonds, I can’t help but wonder about a bunch of things.

I have a 1.11ct L VVS2 AVC ering, and a pair of recently acquired OMC earrings, estimated at around 1ct each, EGL G-H, SI2 (one has visible, but tidy, inclusions under the table that don’t bother me, the other is more or less eye clean (to my eye)).

I spend waaaay too much time “studying” all these stones, comparing them, looking at them in every possible lighting environment, from every angle, etc. In the process of my studies I’ve come up with some questions, and I hope people who have seen more stones than I could help me out.

1. Does color affect the type of colors the stone will reflect? More specifically, my AVC seems to produce way more colors on a more consistent basis than the OMCs. It almost always has some color on its facets. I don’t know whether this is because it is precision cut, or because its main facets are at least twice as big & broad as the OMC ones, or whether the L color contributes to the pastel reflections.

2. My absolute favorite type of “performance” is when the stones light up with every imaginable pastel color. This usually happens in the late afternoon, with indirect sunlight. The pinks, lavenders, purples, greens, light blues… ah, they make me weak in the knees Both the OMCs and the AVC do this. I wonder – do RBs exhibit the same behavior? I’ve never owned an RB, so I’m really curious how they behave.

3. I was also curious about the various types of performance (white light reflections, color play, vs. fire). But I’m not sure how to phrase this one. I guess what is more characteristics for various types of cuts (particularly antique and antique-style vs. RBs)? I think I seen plenty of every one of those categories in all three of my stones though, so this isn’t a burning question on my mind.

4. I take the metro to work and creepily stare at other ladies’ erings Every now and then I see ones that look like icy cold water. I usually see them from the side (how I *wish* I could look some of them in the “face”!)… so I wonder, what produces that clear, cold water look? Is it high color, or some aspect of the cut? Or maybe they’re just super clean But when I clean my stones, they look pretty but still mostly white… there is always some reflection going on. The “metro” stones look dark… but somehow mesmerizing at the same time. These stones are also usually pretty big. I wonder if that’s a factor.

5. For non-precision cut stones, what would be the signs of a stone being too deep or too shallow? As I stare and stare at the OMCs, they sometimes totally light up with whiteness. Sometimes the facets under the table are asleep. Sometimes one or two catch the light. The AVC is more consistent in its behavior. I can’t figure it out… if the OMCs were too deep or shallow, would there still be some reflections off the center facets? Just not as consistent?

6. Related to the previous question, I wonder about this JbEG stone: http://jewelsbyericagrace.smugmug.com/Jewelry/Loose-Diamonds/118ct-Old-European-Cut-Diamond/21556399_p9tkn5#!i=1718838443&k=CqPC6t8

How can it be 7+mm at 1.18 ct weight? It has to be too shallow, right? Too bad the video is so blurry, but it doesn’t look absolutely awful… what would be the problem with it (if any) when looking at it IRL?

7. Lastly, if anyone can recommend any good books on diamonds or antique jewelry, I’d appreciate it .

I think this is all I can think of for now. I’d appreciate any answers to any of the questions!

- Anya

 

[GemFever]

No takers? I wonder if my questions may have come too soon after the somewhat heated AVC/AVR vs. OMC/OEC discussion. It's not my intention at all to bring any of that up. I'm only very curious to find out about a couple things ... maybe I'll narrow down my questions:

- does a warmer diamond tend to produce more pastel reflections? Does warmth affect performance in any way?

- do modern round brilliants give off the pastel reflections that stones with chunkier facets do?

If anyone can direct me to any educational info or previous threads, I'd appreciate that too.

Cheers!

 

[Dreamer_D]

1. Does color affect the type of colors the stone will reflect? More specifically, my AVC seems to produce way more colors on a more consistent basis than the OMCs. It almost always has some color on its facets. I don’t know whether this is because it is precision cut, or because its main facets are at least twice as big & broad as the OMC ones, or whether the L color contributes to the pastel reflections.

It is debated, and apparently the concensus is "no". But in my experience low color stones show a much wider range of apparent color. The body tint seems to interact with environmental colors to create more extreme variation.

2. My absolute favorite type of “performance” is when the stones light up with every imaginable pastel color. This usually happens in the late afternoon, with indirect sunlight. The pinks, lavenders, purples, greens, light blues… ah, they make me weak in the knees Both the OMCs and the AVC do this. I wonder – do RBs exhibit the same behavior? I’ve never owned an RB, so I’m really curious how they behave.

Not the same way, but I think its just because the facets are smaller and you cannot perceive the colors as easily.

3. I was also curious about the various types of performance (white light reflections, color play, vs. fire). But I’m not sure how to phrase this one. I guess what is more characteristics for various types of cuts (particularly antique and antique-style vs. RBs)? I think I seen plenty of every one of those categories in all three of my stones though, so this isn’t a burning question on my mind.

I find that well cut stones of any ilk produce all those type of light. I find RBs look a bit brighter and the speed of scintillation is faster, making them more eye catching than cuts with bigger facets which can have slower scintillation. Older cuts also tend to have more fire -- all else being equal (which it never is). But well cut stones should be balanced to a degree, in my opinion, and look good in all lighting. But comparing head to head, some lights might favour one cut over another.

4. I take the metro to work and creepily stare at other ladies’ erings Every now and then I see ones that look like icy cold water. I usually see them from the side (how I *wish* I could look some of them in the “face”!)… so I wonder, what produces that clear, cold water look? Is it high color, or some aspect of the cut? Or maybe they’re just super clean But when I clean my stones, they look pretty but still mostly white… there is always some reflection going on. The “metro” stones look dark… but somehow mesmerizing at the same time. These stones are also usually pretty big. I wonder if that’s a factor.

Hmm. I am not sure what you are describing here.

5. For non-precision cut stones, what would be the signs of a stone being too deep or too shallow? As I stare and stare at the OMCs, they sometimes totally light up with whiteness. Sometimes the facets under the table are asleep. Sometimes one or two catch the light. The AVC is more consistent in its behavior. I can’t figure it out… if the OMCs were too deep or shallow, would there still be some reflections off the center facets? Just not as consistent?

Two issues likely: too deep, and poor symmetry of the under table facets. Creates a more random and less predictable on-off patterning.

6. Related to the previous question, I wonder about this JbEG stone: http://jewelsbyericagrace.smugmug.com/Jewelry/Loose-Diamonds/118ct-Old-European-Cut-Diamond/21556399_p9tkn5#!i=1718838443&k=CqPC6t8

How can it be 7+mm at 1.18 ct weight? It has to be too shallow, right? Too bad the video is so blurry, but it doesn’t look absolutely awful… what would be the problem with it (if any) when looking at it IRL?

The depth is 48%, which is so low that I would be surprised if the stone looks great accross a wide array of lighting. Leakage seems evident under the table. But these old stones are strange little beasties. I had a stone with a crown about 10-12%, so low that if I saw only a photo I would say "no way!" But it worked with the pavilion and the stone was divine. It had a deep pavilion though. But those old timey cutters did know what they were doing. Most of them.

 

[webdiva]

What a fascinating topic! I hope to own an OEC or tranny cut someday!

As for the colors your AVC shoots off, my Princess of Hearts actually shows more fire than scintillation in many lighting situations but the colors it shoots off are more primary colors (red, yellow, blue). Hubby is mesmerized by the colors! So am I! The elevator at work, my bathroom chandelier with GE Reveal bulbs and walking the dogs in the morning show the most fire.

 

[GemFever]

Thanks Dreamer! This is exactly what I was looking for. I'm also leaning towards the idea that a warmer stone shows more pastel color play... but try I'll to do a search here to see what people have said.

Webdiva -- I love your ring. Interesting what you say about the mostly primary colors... but your princess of hearts is probably close in nature to a H&A round? I've gotta get my hands on a "faster" stone sometime soon so I can study it