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Glowy blue sapphires: what are reasonable expectations?

deorwine

Shiny_Rock
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May 5, 2005
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348
Athenaworth's recent post on her JW sapphire made me post something I've been thinking about for some time: how well should one expect a really nice sapphire to do in very low lighting?

I have a lovely medium blue sapphire that does seem to glow in sunlight. Even inside, in artificial lighting. it does pretty well-- as long as it is getting some light from a light source (light bulb, diffused window sunlight, etc., even if the light source is fairly weak). BUT if you turn it away from the light source it seems to become very dull and bleah and almost inky. I also have a small Mahenge spinel from Tan, where if you turn it away from the light source it is still a glowing fiery pinkish-orange-red.

I know some of it must be that the spinel is lighter toned than the sapphire, but I don't think it is by much, and I see the same thing with a sapphire I own that's almost a sky blue color.

My medium-blue sapphire is native cut -- maybe a precision cut would help, but I don't really think that's the problem either. The darker ring in my pics has a precision cut sapphire, though it's bezel set and darker to begin with, so it's not quite a fair comparison.

Soo... are my expectations just too high if I expect a sapphire to perform like a Mahenge spinel? Or if I had a top-end sapphire would it perform like that? (And if that's so, why -- is it because it's got "sleepy" inclusions? And how can I find these top-end sapphires?)

My pictures are awful, but here are a couple that might sort-of-kind-of demonstrate what I mean. The spinel looks much more vibrant (and more of an orangey-red than the straight pink it looks here) in real life, but you sort of get the idea that it is sparkly even in low light, and a vivid color. The sapphire on top is the precision cut darker one, and goes black in indoor lighting... outdoors it is pretty. The sapphire on bottom is my medium-ish toned one and looks brighter than the pic in sunlight, but you get the idea; in low light it's not entirely black, but that is about it.

P1030010.jpg

P1030006.jpg
 

athenaworth

Ideal_Rock
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Thank you for posting this question. I'm curious about this as well and you worded it much better than I would've. :D

ETA: beautiful Mahenge spinel btw :cheeky: :cheeky:
 

Arcadian

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empress

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Blue and red (pink) respond differently to light. No, they will never perform the same. When buying blue sapphires and rubies, you look at them at different times of the day based upon the color make-up of the daylight.
 

T L

Super_Ideal_Rock
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The sapphires are darker in tone than the Mahenge so you're not going to get the same brightness from them in low light sources that you will from a pink stone. I think it's reasonable to expect a lighter toned sapphire to show some brightness in low level lighting situations, but some people do not like lighter toned sapphires. I have a lighter toned sapphire that does this, and it has nice color too.

As far as saturation goes, a good Mahenge will always show a tremendous amount of saturation in the sun due to strong UV fluorescence, which a sapphire does not have. I think that's why fine red stones, like rubies, are so highly prized as they also have strong UV fluorescence as well.

Now what you've described above is just a lack of lighting, which can make a dark toned stone appear darker, but if you were to shine a regular artificial light on it, be it fluorescent, or incandescent, I hope it would retain most if not all of it's saturation. A fine sapphire should not do is go very grey or extinct in regular indoor lighting conditions, and some tend to do this.
 

Pandora II

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You can't expect a blue stone to perform like a red stone.


There are 3 factors that go into how you will see a colour:

1) You: your own levels of colour perception (genetically 1 in 250 women and 1 in 12 men have a genetic colour deficiency), your eyesight, your health, how tired you are.

2) The light source:
Natural Light: All the wavelengths of the visible spectrum from red to violet are evenly spaced and close together.

Artificial Light: Incandescent light has very strong levels of red light and very weak levels of blue light.

(To keep things simple I'm not going to get into other light sources but same principle applies. Also worth noting that with things like daylight bulbs they are not necessarily that similar to daylight and one daylight bulb can have very different areas of weakness and strength from other daylight bulbs)

3) The object: Different gemstones will absorb light in different ways according to their chemical make-up. The result of this selective absorbtion is that we see the stone as a certain colour. The trace elements in the chemistry of a ruby absorb all the light wavelengths except red which is reflected back to us and so we see the stone as red.

If you have a blue sapphire and you are looking at it under an incandescent light source that is very weak in blue light, it is going to look inky and black because there is not enough blue light to reflect back to our eyes. Look at a ruby under the same light source and it will look pretty amazing as whatever blue light there is will be absorbed anyway but the very strong red will reflect back to your eyes making the stone appear even redder.

Look at the two stones again in daylight and the blue stone will show its blue colour at its best, and the red stone won't look quite as good. They will also look different in the morning, at noon and in the afternoon as there is more red light in the morning (buy blue sapphires in the am) and more blue in the afternoon (sell blue sapphires in the pm) :Up_to_something:

This is why the whole 'holding its colour in all lights' is so ridiculous. If there is no blue light then a blue stone CANNOT look blue no matter how amazing a stone it is. The best you can hope for is that a stone looks okay in most lights. Some species will always look crap in certain lights.

The issue is 99% with the light source you are using. It has nothing to do with how good the stone is, or saturation or anything like that, Purely whether the light is rich in one colour or another and whether that is the colour of the stone.
 

T L

Super_Ideal_Rock
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Pandora did a nice write up. I will just say that I believe you are using natural lighting, and you are holding your hand up against the light with the stones facing you so that they don't have much light on them. I have seen sapphires that still looked great under such conditions, and very bright. If that's not the lighting conditions to which you photographed the stone, than please correct me.

Here's a thread with a sapphire taken under such lighting conditions to give you an example. It doesn't appear that bright light was used in any of these photos either. There are some photos in this thread with the sapphire next to a Mahenge spinel, so you can compare the two as well. There's actually one dim shot where the sapphire looks more bright than the mahenge. However, both are really nice stones. I like Ceylon sapphires, as in the below thread, as they tend to be lighter in tone, while still retaining very nice saturation. Again, I think this helps the viewing pleasure in dim light situations.

https://www.pricescope.com/community/threads/ss-big-blue-ring-has-arrived.142570/
 

deorwine

Shiny_Rock
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May 5, 2005
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348
athenaworth, thanks!

Arcadian and empress, thanks for the info -- it makes sense that given the very different crystal structures that they're going to have different optical properties.

Wow, Pandora, you wrote a book for me! That is awesome! I am going to have to bookmark it and refer to it every time I look at my sapphires in different lighting conditions :)

TL, my sapphire does indeed hold saturation in different lighting conditions, or if it doesn't I can't tell, which is what counts, right? :) I am indeed using natural lighting in both those pictures, with my hand held up so the light is falling on it in the first picture and so that the light is falling on my palm instead in the second picture.

I really like that thread you posted to, and I think there is my answer: I thought medium tone was good enough, but that "big blue" sapphire is medium-light, and I can see that it makes a huge difference in the low-light performance, comparing sleepyspinel's pics and mine. I guess one of the takeaways here is that I can't judge tone very well :)

As I mentioned in the OP, I do have another medium-light sapphire, but it does lose a lot of saturation in non-sunlight lighting conditions (which is how I was looking at it when I declared it was all dark and bleah), so I think that's what is going on with that stone -- I'll have to look at it in dim sunlight and see if it retains a pretty color then.
 

Arkteia

Ideal_Rock
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On an emotional side, I understand your frustration very well because it is irritating to see a stone that becomes inky indoors. But you can be lucky, and my sapphire from Gary Braun maintains its color. Since that purchase, I was not able to find a similar stone but I keep looking...
On a very positive note - your spinel is beautiful.
 

deorwine

Shiny_Rock
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May 5, 2005
Messages
348
crasu, what tone would you say your sapphire was? Medium-light or darker? Do you have pics?
 
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