Pad sapphire going colorless in some light'' condition?

[lovegem]

My SIL has a pad sapphire (she just knows it is a sapphire, but from the special beautiful orange-pinkish red color, I am guessing it is a pad). She told me that she saw her pad going colorless in some kind of light condition once. She was in an exhibition event and there were different lighting systems there. She kinda freaked out when she saw the stone that day at that time. Unfortunately she doesn't remember what sort of light that caused the pad turning colorless. Does anyone know if a really Pad would behave like this? any explanation at all?

BTW, she gave me a 5 stone ruby/diamond ring as our wedding gift.

Will post pics soon.

 

[cssuja]

Hi,

I have a few padparadscha sapphires, bought from the NSC. They display slight colour change depending on the light conditions. In some lights, these stones are pastel coloured (light pink/orange/mixture of both). But I have never seen them go completely ''colourless''.

 

[ptorraca]

Many gems will exhibit a color shift depending on the light source. The color of a gem is due to it''s molecular makeup interacting with available light. Thus, varied light will give varied colors, to a certain extent. Really, this isn''t unique to gems. Ever notice how a "white" shirt will look very slight bluish in fluorescent office light and maybe have a very slightly orange tone in the light of a gymnasium?

A color change is going from one hue to another hue -- say, red to green. A color shift is more subtle. It could be something like some amethyst sometimes displays, going from a reddish purple to a violet purple. In that case, it''s not a color change because the purple is always present. We call it a color shift because it is "shifting" between variations of the same color.

It''s just a guess, but exhibition halls are often lit with those large tungsten lamps from the ceiling. Those lights are strong enough to make things looks quite different compared to daylight (which is why many gem dealers carry their own light for exhibits). I would expect an orangy pink stones to look washed out in that environment.

Now, all of that being said -- is she absolutely sure it''s a sapphire? I have seen some garnets that go from a pink to a light tan -- I could see them being described as colorless given the right environment. (Remember, how you perceive gem color is influenced by the whole environment: the lights, the shirt you''re wearing, the color of the walls, tired eyes, etc.)

 

[innerkitten]

Which lighting does it go colorless in?

I''d love to see your new ruby ring.

 

[innerkitten]

Oops I re read and you said she doesn''t remember. I guess some types of light block out certain colors a little.

 

[zeolite]

Date: 9/6/2008 4:24:33 AM
Author:lovegem
My SIL has a pad sapphire (she just knows it is a sapphire, but from the special beautiful orange-pinkish red color, I am guessing it is a pad). She told me that she saw her pad going colorless in some kind of light condition once. She was in an exhibition event and there were different lighting systems there. She kinda freaked out when she saw the stone that day at that time. Unfortunately she doesn't remember what sort of light that caused the pad turning colorless. Does anyone know if a really Pad would behave like this? any explanation at all?

BTW, she gave me a 5 stone ruby/diamond ring as our wedding gift.

Will post pics soon.

Let's assume that her pad had a small amount of orange and a large amount of pink.

Look at the spectrum charts below. Look at the leftmost chart, daylight. It has about equal amounts of orange and pink (light red). Under daylight, her gem would look normal.

Look at the 3rd chart, daylight fluorescent. It has about the same amount of orange as daylight, but amost no red, compared to daylight. Under a daylight fluorescent, the pink would nearly disappear, and she would only see a pale orange gem, much different from daylight. It isn't that some lights block out colors, but that some light sources have almost none of that color. Red stones and red dresses look terrible under normal (not full spectrum) fluorescents.

 

[ptorraca]

Excellent Zeolite! Much better than my wordy reply. Where did you get those charts?

 

[zeolite]

I hope I am not violating any policy here about links. This is a lamp company, has nothing to do with jewelry:

http://www.atlantalightbulbs.com/excella.html

 

[lovegem]

Thanks ptorraca, innerkitten, and Zeolite.
Zeolite, your chart is very informative, I will show my SIL.

 

[Linda W]

Date: 9/6/2008 9:59:13 AM
Author: Anita
Hi,


I have a few padparadscha sapphires, bought from the NSC. They display slight colour change depending on the light conditions. In some lights, these stones are pastel coloured (light pink/orange/mixture of both). But I have never seen them go completely ''colourless''.

I love your Pads Anita.


Linda

 

[Linda W]

Date: 9/8/2008 11:27:50 AM
Author: zeolite
I hope I am not violating any policy here about links. This is a lamp company, has nothing to do with jewelry:


http://www.atlantalightbulbs.com/excella.html

Thank you so much zeolite for this information. It is really helpful.


Linda

 

[GemRite]

The only pad sapphires i have dealt with are the ones from Tanzania. Actually the Umba Valley. They are a really nice pink with slight orange in incadescent light, and in flourescent light the stones are a nice mix of pink and orange, and in natural sunlight they are orange with a slight pink. They have been hard to find in rough, but when they come in I jump fast. Of course these stones are untreated, I am not certain what happens to stones when they diffuse the color in with Be. These stones still show the dichrosim, so when you see the stone cut you literally see the pink and orange in the gem at the same time. The ones I have cut are untreated and unheated. Nice stones! I have never heard of them going clear.

 

[Lupinbunny]

GemRite: I had no idea that sapphire are/ can be dichroic! Is that normal and I didn''t know it, or are some dichroic and some not? Does the dichroism show when you tilt the stone? I have iolite earrings that I can spend hours with - tilt them the right way and all the purple drains away! Can this be why sapphires are sometimes a different colour when you tip them upside down, or is that just colour zoning showing?

 

[GemRite]

Yes, sapphires are dichroic, but not as strong as some other stones stones. For instance sapphires show orange one direction and turn the stone it will be a pink. Blue sapphires can be a green blue on direction and a royal blue down the axis. Yes it is common for all sapphires and one of the quick ways to just eye out a garnet from a ruby. The ruby will show a red pink and a purple. It''s dichroism may not be as dramatic as iolite and tanzanite. But can often tell by rotating the stone in light. Of course this is easier with rough, but a dichroscope is in my bag of tools for sure.