Why/how Alexandrite does what it does

[kenny]

I found this interesting so I thought I'd share it.

Kinda geeky ...

http://www.chemistry-blog.com/2013/08/22/alexandrite-effect-not-all-white-light-is-created-equal/

 

[Marlow]

Very interesting!

Additional for the strongly trichroitic alexandrite the orientation of the cut is important for the color change too.

And unfortunately the best daylight color is parallel to the a-axis and the best incandescent color parallel to the b axis.

And... the rough is often twinned...

It is sooo easy in CC garnet!!!

 

[minousbijoux]

So here is a Brazilian alex I have. I took it outside today around 1:00 pm and in the direct sun, it just acted all confused (first pic). Then I took it out of direct sunlight to bright indirect sunlight and then it acted like a proper alex. I find the photo quite accurate, but in hand, it was ever so slightly bluer than the pic.

So Marlow, have any advice on how I can pump up the wattage on the few incandescent lights I have left in my home (mostly CFLs now) to really see its red/purple side?

 

[liao]

Very interesting!

Additional for the strongly trichroitic alexandrite the orientation of the cut is important for the color change too.

And unfortunately the best daylight color is parallel to the a-axis and the best incandescent color parallel to the b axis.

And... the rough is often twinned...

It is sooo easy in CC garnet!!!

wow, Marlow! are you happen to be a scientist or gemologist?

So here is a Brazilian alex I have. I took it outside today around 1:00 pm and in the direct sun, it just acted all confused (first pic). Then I took it out of direct sunlight to bright indirect sunlight and then it acted like a proper alex. I find the photo quite accurate, but in hand, it was ever so slightly bluer than the pic.

So Marlow, have any advice on how I can pump up the wattage on the few incandescent lights I have left in my home (mostly CFLs now) to really see its red/purple side?

how do you capture the green spectrum of your alex?

 

[Marlow]

First, I like this alex!

Nice balanced daylight color - not to dark. Is it a stone from Multicolorgems?

I still use a 60 Watt bulb - an old one - and the lamb I got with my refractometer - these lambs are used in medicine course you need these lamps to see scarlett fever for example.

I will get in a few week a small but very nice russian EC alexandrite - a visible twinned stone - good change and I am looking forward to see it in different light conditions. The vendor has an Ph. D. in mineralogy and collected these stones in Russia. He showed me and Dr. Schmetzer several russian and brazilian alexandrite - among the russian stones a very long oval and a pear with an extremely nice change.

I will try to get them too.

Most Alex was from Sri Lanka - I saw one or two nice stones - but to expensive for this quality.

 

[Marlow]

Very interesting!

Additional for the strongly trichroitic alexandrite the orientation of the cut is important for the color change too.

And unfortunately the best daylight color is parallel to the a-axis and the best incandescent color parallel to the b axis.

And... the rough is often twinned...

It is sooo easy in CC garnet!!!

wow, Marlow! are you happen to be a scientist or gemologist?



No - page 111 ff "Russian Alexandrite" Dr. Karl Schmetzer

 

[liao]

Very interesting!

Additional for the strongly trichroitic alexandrite the orientation of the cut is important for the color change too.

And unfortunately the best daylight color is parallel to the a-axis and the best incandescent color parallel to the b axis.

And... the rough is often twinned...

It is sooo easy in CC garnet!!!

wow, Marlow! are you happen to be a scientist or gemologist?



No - page 111 ff "Russian Alexandrite" Dr. Karl Schmetzer

I am pretty sure that I own that book, but I cannot find it in my shelf. Perhaps, I left that book in europe (I just move to US two months ago)

 

[Marlow]

This book is great - I only don't like the pictures - he needs a better fotograf.

 

[minousbijoux]

First, I like this alex!

Nice balanced daylight color - not to dark. Is it a stone from Multicolorgems?

I still use a 60 Watt bulb - an old one - and the lamb I got with my refractometer - these lambs are used in medicine course you need these lamps to see scarlett fever for example.

I will get in a few week a small but very nice russian EC alexandrite - a visible twinned stone - good change and I am looking forward to see it in different light conditions. The vendor has an Ph. D. in mineralogy and collected these stones in Russia. He showed me and Dr. Schmetzer several russian and brazilian alexandrite - among the russian stones a very long oval and a pear with an extremely nice change.

I will try to get them too.

Most Alex was from Sri Lanka - I saw one or two nice stones - but to expensive for this quality.

Hmm, I'm actually not sure I have any of those old incandescent bulbs around, but I will look and see if I can capture anything, or whether it will just register as a dark blob...

 

[minousbijoux]

I did it! The alex was like a geiger counter; as I took it around the house, it showed me the one and only incandescent lightbulb we have in the whole house - the living room overhead light. So I managed some pics - they aren't the greatest, as its not a terribly bright overhead light, but hey, I got some at least.

 

[FrekeChild]

That looks so awesome MB!

 

[Marlow]

OMG!!!

This stone is fantastic!!!!! I am really jealous!!!

Please post the second shot ( indirekt sunlight) and one of these 3 shots in one post and please could somebody copy them into the "alex" topic!!!

Do you have the weight and again - is it from Multicolorgems??

 

[minousbijoux]

OMG!!!

This stone is fantastic!!!!! I am really jealous!!!

Please post the second shot ( indirekt sunlight) and one of these 3 shots in one post and please could somebody copy them into the "alex" topic!!!

Do you have the weight and again - is it from Multicolorgems??

Is this what you mean Marlow? It is about 1.7 cts and its from an Intergem vendor several years ago (had I been smart, I would've bought from Multicolour and saved $$ for sure). Thanks for the kind words.

 

[Marlow]

1,7 ct Hematita alexandrite!!! I am def. jealous!!

Again this stone is a perfect example for a color change and very fine!! Most are darker ( I still love this) but this is a perfect balanced daylight and incandescent light alex!

Thank you for the picture.

 

[digdeep]

OMG!!!

This stone is fantastic!!!!! I am really jealous!!!

Please post the second shot ( indirekt sunlight) and one of these 3 shots in one post and please could somebody copy them into the "alex" topic!!!

Do you have the weight and again - is it from Multicolorgems??

Is this what you mean Marlow? It is about 1.7 cts and its from an Intergem vendor several years ago (had I been smart, I would've bought from Multicolour and saved $$ for sure). Thanks for the kind words.

Thank you for these photo's!! OMG, both colors are BEAUTIFUL, what a treasure!!!

 

[minousbijoux]

Thanks for the compliments. Now I have to go look up Hematita alexandrite...

 

[Starzin]

Minou! You've been holding out on us! What a beautiful stone, and fantastic that you captured the elusive colour change. Why oh why is it still unset?

 

[chrono]

Perfect colours - the last time I saw such nice change and colours on both ends was at least 10 years ago.

 

[minousbijoux]

Thank you, Chrono, for such kind words. The fact is that much of the time, the lighting is mixed, so the stone is not at one extreme or another, unfortunately.

 

[LoversKites]

It really is beautiful. Dramatic change indeed. How's it like in mixed light?

 

[minousbijoux]

It really is beautiful. Dramatic change indeed. How's it like in mixed light?

It looks similar, perhaps a bit more colorful, than the first pic I took, back upthread. Its the look I call muddy, just because the purple and green make a kind of muddled I-don't-know-what-I-am color.

 

[pregcurious]

Wow, I don't think I've seen such a well cut, strong color-changing alex on PS before. Minou!

What country is it from?

Here is a smaller alex with a window. It is $6560!
http://www.multicolour.com/detail/?1110829089

 

[LoversKites]

It really is beautiful. Dramatic change indeed. How's it like in mixed light?

It looks similar, perhaps a bit more colorful, than the first pic I took, back upthread. Its the look I call muddy, just because the purple and green make a kind of muddled I-don't-know-what-I-am color.

The poor thing has identity issues. The extremes are fantastic, at least.

 

[minousbijoux]

It really is beautiful. Dramatic change indeed. How's it like in mixed light?

It looks similar, perhaps a bit more colorful, than the first pic I took, back upthread. Its the look I call muddy, just because the purple and green make a kind of muddled I-don't-know-what-I-am color.

The poor thing has identity issues. The extremes are fantastic, at least.

Haha, exactly right!

Preg: its from Brazil.

 

[pregcurious]

I love the green hue. Aren't many from Brazil steel blue?

 

[LoversKites]

I love the green hue. Aren't many from Brazil steel blue?

That's what I've noticed too.

 

[Marlow]

Think, direct sunlight, esp. in the evening and morning is a bit "warmer" - don't know how it works but I noticed this with alex and CCG...

So they show a mixed light.

Otherwise you should be very careful if your alex hates sunlight.....

And becomes bloodred at night....

 

[minousbijoux]

Think, direct sunlight, esp. in the evening and morning is a bit "warmer" - don't know how it works but I noticed this with alex and CCG...

So they show a mixed light.

Otherwise you should be very careful if your alex hates sunlight.....

And becomes bloodred at night....

Okay, Marlow, officially scared here now. Are you saying my alex is possessed by evil?!!! I knew I would likely sell it some day, but now sheesh, its like Annabelle - I'll be afraid to go to sleep when its around!!!

ETA: maybe it won't be able to get out of the bank vault when it goes back there...

 

[Marlow]

Transsylvinian alex.....maybe ?

Try garlic and set it in silver

 

[minousbijoux]

Transsylvinian alex.....maybe ?

Try garlic and set it in silver