fluorescence/extinction in gems?

[firegypsy]

I'm at a loss to understand this.  Perhaps there is an easy answer.  Why does my ruby die under artificial lights of all kinds but perform beautifully in the sun? 

I figured that fluor happened under artificial lights as well....but if I'm in the mall, or a grocery store etc. it just looks black and dead.  Is that extinction?  I'm guessing it is (maybe) but it's the whole stone, not parts of it.  Get it into the sun though and it's mind bogglingly beautiful-just glows red.  What's happening here?

[oldmancoyote]

What is happening is 2 things:

1. Indoor lighting other than "black lights" in discos has virtually no UV, so the fluorescence is not there. This is also why you don't get sunburnt by sitting indoors under bright lights.

2. Sunlight - even on a hazy or cloudy day, or even in the shade of a tree - is considerably brighter than most indoor lighting. The human eye adapts very well to different lighting conditions, so the difference is not as noticeable to you, but the level of lighting is 10-20 times lower indoors, and possibly 50 times lower than direct sunlight, as you can find out by looking at your camera's shutter timing inside/outside.

If it's any consolation, I have a number of stones (diamonds, tourmalines, topazes, sapphires) that look much happier outside - even not in full sunlight - than inside or in any case under artificial lighting.

[firegypsy]

Interesting.  Yes, I'm sitting inside right now, and not even near the window and she's wonderfully red.  However if I were to turn on the overhead light, she'd be very dark again.

I don't mind it, it means that it's a tempermental stone, which is kind of perfect for me.  lol.  I was just curious as to why.  I love the fluor outside though.  It's dazzling.

OMC, you've come through once again!

[Trinkette]

Colored gemstones absorb and return light (seen as color) based upon their chemistry and crystal formation. In general, red stones, like ruby, show their colors best in incandescent light (like candle light) or sun because incandescent light and sun during certain times of day give off mainly red, orange and yellow light waves. SO, these colors will be emphasized in your stone. By contrast, grocery store and mall lighting, in addition to many new energy efficient light bulbs, are often blue- or green-based lighting sources. Basically, blue/green + red = blechhh. (If I were painting and wanted to make grey, this would be one recipe).

[Trinkette]

I've been interested to see how the new energy efficient home lighting will impact the colored gem industry (if at all). The visual impact on colored gems is significant, yet, no one is talking about it.

[Trinkette]

Off to market... 

[firegypsy]

I've been interested to see how the new energy efficient home lighting will impact the colored gem industry (if at all). The visual impact on colored gems is significant, yet, no one is talking about it.

I am!

It's just baffling and there's something with my stone, because even in jewelry stores where rubies look red, mine doesn't.  I've very aware that their rubies probably aren't rubies at all, which could account for this-but in places like Tiffanys?  I would expect my stone to look better.  Ah well.

The new lighting does wonders for my diamond though!  I guess that's a plus?  Maybe?

[clgwli]

At least in our local Tiffany store, unless you have your ring in the case the lighting is pretty poor.  I noticed when looking at their yellow diamonds they looked fantastic in the case, but the moment you get out into the room they were kind of dull by comparison.

I haven't been to the flagship store in NYC or Chicago, but our lighting is very yellow and very dull.  Not at all what you would expect of a real jewelry store.  Their cases are well lit I will say but the rest kind of sucks.

We have a lot of CFLs in my home and a lot of them seem to wash out color/vibrancy on any of my colored stones.  I'd rather sit by the window and get slightly diffused sunlight than use CFLs for showing off how lovely a stone is.  Even my brightest kitchen lights wash color out (including skin/clothing)

[oldmancoyote]

Bear in mind that in most jewellery stores the lighting is focused on the jewels, not the surroundings... which is why "their" stuff looks great, and "yours" looks - erm - meh.

[firegypsy]

touche.

[oldmancoyote]

I've been interested to see how the new energy efficient home lighting will impact the colored gem industry (if at all). The visual impact on colored gems is significant, yet, no one is talking about it.

Off to market... 

For coloured gems, light bulbs or general shopping?

Actually, you have a point. A big one. I have a few halogens that I keep because at least with them I get decent colour rendition. Gems are a PITA, but paintings are hardly better with fluorescents (for those that don't believe me: just go to Budapest's Museum of Fine Arts...)

[Trinkette]

For coloured gems, light bulbs or general shopping?

None of the above, OMC! I went to buy bags of shavings for my horse's stalls, lol! Had to rush before picking-up DS from school (as it turned out, DH saved the day and got to school before me so I could piddle with horses at the barn, something I rarely do anymore).

Yes, I admit, the whole lighting/gems thingy fascinates me. And, certainly, with paintings as well. it IS huge, I should research...

Please, tell me about Budapest's MFA.

[oldmancoyote]

Well, when I went there (a long time ago, but still well after the USSR break-up), I was stricken by the fact that although there are world-class paintings, the rooms were all lit by dreary fluorescent tubes. Of the bluish-green variety. Fair enough, the building is constructed to exploit natural light outside, but if one goes and visit in a rather dreary November day it isn't fun. Martian, greenish ghosts painted by Raffaello , Bellini, Masaccio, Bronzino, Titian, Durer, Hals, etc. infest the halls.

Maybe things have changed now - the photos on the internet seem to be of a much better kept (and lit) place.

[Trinkette]

Oh wow. Given the subject matter and color palettes of many of these paintings, the experience must have been quite disturbing. So, the lighting was the total opposite from the lighting in which these were created. All the browns and darker colors... mixed with cold light... blecccch. What a weird, unsettling experience that must have been.