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 Post subject: LuAG: Availability & Properties
PostPosted: Sun Mar 20, 2022 9:09 am 
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Hi forum community, would like to know more about LuAG, Lutetium aluminium garnet.

In what way is it made, e.g.fame fusion, hydrothermal etc.?

How is it compared to yellow YAG?
Hue
Colour saturation
Tone
More specifically, fluorescence: colour, intensity. Is this one of the most fluorescent
synthetic mineral material with high hardness & strength?

And knowing it's mainly utilized for laser related purpose, any way to purchase such material for gem use?


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 Post subject: Re: LuAG: Availability & Properties
PostPosted: Sun Mar 20, 2022 1:57 pm 
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I think Arya may be able to shed additional light on this topic.
Till then:
https://en.wikipedia.org/wiki/Lutetium_aluminium_garnet


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 Post subject: Re: LuAG: Availability & Properties
PostPosted: Sun Mar 20, 2022 2:39 pm 
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Barbra Voltaire, FGG wrote:
I think Arya may be able to shed additional light on this topic.
Till then:
https://en.wikipedia.org/wiki/Lutetium_aluminium_garnet

Interesting article. In the Synthesis section it represents that it takes extreme heat to produce for applications as stated and all lower heat processes produce lower optical grade materials.

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 Post subject: Re: LuAG: Availability & Properties
PostPosted: Sun Mar 20, 2022 2:51 pm 
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Stephen Challener has been selling it.


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 Post subject: Re: LuAG: Availability & Properties
PostPosted: Sun Mar 20, 2022 5:59 pm 
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dchallener wrote:
Stephen Challener has been selling it.

What? Where?


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 Post subject: Re: LuAG: Availability & Properties
PostPosted: Sun Mar 20, 2022 9:14 pm 
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ByE wrote:
Hi forum community, would like to know more about LuAG, Lutetium aluminium garnet.

In what way is it made, e.g.fame fusion, hydrothermal etc.?

How is it compared to yellow YAG?
Hue
Colour saturation
Tone
More specifically, fluorescence: colour, intensity. Is this one of the most fluorescent
synthetic mineral material with high hardness & strength?

And knowing it's mainly utilized for laser related purpose, any way to purchase such material for gem use?

It is grown by Czochralski pulling. Compred to yellow YAG it is yellow-green rather than pure yellow. It is also visibly brighter.
My brother spent a long time finding a source for some, and we sent a boule to my friend Eric Bardawil to cut--it's done extremely well on instagram and tiktok this week. The stone he cut is enormous and extremely beautiful, since LuAG also has all the good optical properties of YAG on top of the fluorescence https://www.instagram.com/reel/CbIVIz1N ... =copy_link
I've been selling rough but it has gone fast. I am down to 3-8 gram pieces. We're scrambling to get more--it looks hopeful but nothing is nailed down yet.

As a side note I also just sent Eric a giant ~250g boule top of the classic Ce:YAG which should cut an even bigger stone.

Here is a comparison of some Ce:YAG and Ce:LuAG. Note the uv flashlight is aimed a ways away from the stones.
Image

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 Post subject: Re: LuAG: Availability & Properties
PostPosted: Tue Mar 22, 2022 9:41 am 
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Stephen Challener wrote:
ByE wrote:
Hi forum community, would like to know more about LuAG, Lutetium aluminium garnet.

In what way is it made, e.g.fame fusion, hydrothermal etc.?

How is it compared to yellow YAG?
Hue
Colour saturation
Tone
More specifically, fluorescence: colour, intensity. Is this one of the most fluorescent
synthetic mineral material with high hardness & strength?

And knowing it's mainly utilized for laser related purpose, any way to purchase such material for gem use?

It is grown by Czochralski pulling. Compred to yellow YAG it is yellow-green rather than pure yellow. It is also visibly brighter.
My brother spent a long time finding a source for some, and we sent a boule to my friend Eric Bardawil to cut--it's done extremely well on instagram and tiktok this week. The stone he cut is enormous and extremely beautiful, since LuAG also has all the good optical properties of YAG on top of the fluorescence https://www.instagram.com/reel/CbIVIz1N ... =copy_link
I've been selling rough but it has gone fast. I am down to 3-8 gram pieces. We're scrambling to get more--it looks hopeful but nothing is nailed down yet.

As a side note I also just sent Eric a giant ~250g boule top of the classic Ce:YAG which should cut an even bigger stone.

Here is a comparison of some Ce:YAG and Ce:LuAG. Note the uv flashlight is aimed a ways away from the stones.
Image


Thanks for the info. The green hue is easy to spot on. The photo also shows an obvious difference in not only the colour of the fluorescence, but also it’s intensity. It’s a really eye catching and interesting material, and I am really curious about it.

I watched the posts on IG, one of the videos indicated a certain silky (which also looks glowy) appearance under direct sunlight, is it caused by its fluorescence? Does it mean natural sunlight is enough to make this material fluoresce?

Also I would appreciate if you could elaborate more on its performance, both in terms of brightness and colour behaviour, in various lighting conditions, eg low light, fluorescent lighting, incandescent lighting etc.

And per your experience, is there any other materials comparable to luAG’s optical properties say synthetic red/pink or cobalt spinel etc?

Thanks a lot.


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 Post subject: Re: LuAG: Availability & Properties
PostPosted: Tue Mar 22, 2022 9:45 am 
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Stephen Challener wrote:
ByE wrote:
Hi forum community, would like to know more about LuAG, Lutetium aluminium garnet.

In what way is it made, e.g.fame fusion, hydrothermal etc.?

How is it compared to yellow YAG?
Hue
Colour saturation
Tone
More specifically, fluorescence: colour, intensity. Is this one of the most fluorescent
synthetic mineral material with high hardness & strength?

And knowing it's mainly utilized for laser related purpose, any way to purchase such material for gem use?

It is grown by Czochralski pulling. Compred to yellow YAG it is yellow-green rather than pure yellow. It is also visibly brighter.
My brother spent a long time finding a source for some, and we sent a boule to my friend Eric Bardawil to cut--it's done extremely well on instagram and tiktok this week. The stone he cut is enormous and extremely beautiful, since LuAG also has all the good optical properties of YAG on top of the fluorescence https://www.instagram.com/reel/CbIVIz1N ... =copy_link
I've been selling rough but it has gone fast. I am down to 3-8 gram pieces. We're scrambling to get more--it looks hopeful but nothing is nailed down yet.

As a side note I also just sent Eric a giant ~250g boule top of the classic Ce:YAG which should cut an even bigger stone.

Here is a comparison of some Ce:YAG and Ce:LuAG. Note the uv flashlight is aimed a ways away from the stones.
Image


Thanks for the info. The green hue is easy to spot on. The photo also shows an obvious difference in not only the colour of the fluorescence, but also it’s intensity. It’s a really eye catching and interesting material, and I am really curious about it.

I watched the posts on IG, one of the videos indicated a certain silky (which also looks glowy) appearance under direct sunlight, is it caused by its fluorescence? Does it mean natural sunlight is enough to make this material fluoresce?

Also I would appreciate if you could elaborate more on its performance, both in terms of brightness and colour behaviour, in various lighting conditions, eg low light, fluorescent lighting, incandescent lighting etc.

And per your experience, is there any other materials comparable to luAG’s optical properties say synthetic red/pink or cobalt spinel etc?

Thanks a lot.


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 Post subject: Re: LuAG: Availability & Properties
PostPosted: Tue Mar 29, 2022 9:44 pm 
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Hey! Can provide some more info.

Refractive index - 1.84
Dispersion - 0.025
Pleochroism - none (isotropic/cubic)
Colour change - almost none (daylight, daylight LED, warm LED, daylight CFL, warm CFL, incandescent)

Production method - pulled, typically Czochralski
Typical dopant - almost exclusively Ce3+ >>> Ce4+, lime green colour

Unique features - absurd, comically extreme fluorescence in outdoor lighting, noticeably greater than Ce:YAG

@ByE - to answer your question, the only gem materials that are anything remotely similar are Ce:YAG and iron-free ruby. For Ce:LuAg, Ce:YAG, and Cr:Al2O3, the fluorescence output colour closely matches the colour of the material in natural light, which leads to a "glow" effect. Certain synthetic spinels that are highly doped with manganese and a few other components have a yellowish-green colour and strong green fluorescence, but their reaction to daylight isn't as intense as the others.


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 Post subject: Re: LuAG: Availability & Properties
PostPosted: Wed Nov 23, 2022 4:08 am 
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Faceting 101 by Arya wrote:
Hey! Can provide some more info.

Refractive index - 1.84
Dispersion - 0.025
Pleochroism - none (isotropic/cubic)
Colour change - almost none (daylight, daylight LED, warm LED, daylight CFL, warm CFL, incandescent)

Production method - pulled, typically Czochralski
Typical dopant - almost exclusively Ce3+ >>> Ce4+, lime green colour

Unique features - absurd, comically extreme fluorescence in outdoor lighting, noticeably greater than Ce:YAG

@ByE - to answer your question, the only gem materials that are anything remotely similar are Ce:YAG and iron-free ruby. For Ce:LuAg, Ce:YAG, and Cr:Al2O3, the fluorescence output colour closely matches the colour of the material in natural light, which leads to a "glow" effect. Certain synthetic spinels that are highly doped with manganese and a few other components have a yellowish-green colour and strong green fluorescence, but their reaction to daylight isn't as intense as the others.


Hey, thanks for the extra info, I'm interested in LuAG too.


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 Post subject: Re: LuAG: Availability & Properties
PostPosted: Thu Sep 21, 2023 6:38 am 
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Stephen Challener wrote:
ByE wrote:
Hi forum community, would like to know more about LuAG, Lutetium aluminium garnet.

In what way is it made, e.g.fame fusion, hydrothermal etc.?

How is it compared to yellow YAG?
Hue
Colour saturation
Tone
More specifically, fluorescence: colour, intensity. Is this one of the most fluorescent
synthetic mineral material with high hardness & strength?

And knowing it's mainly utilized for laser related purpose, any way to purchase such material for gem use?

It is grown by Czochralski pulling. Compred to yellow YAG it is yellow-green rather than pure yellow. It is also visibly brighter.
My brother spent a long time finding a source for some, and we sent a boule to my friend Eric Bardawil to cut--it's done extremely well on instagram and tiktok this week. The stone he cut is enormous and extremely beautiful, since LuAG also has all the good optical properties of YAG on top of the fluorescence https://www.instagram.com/reel/CbIVIz1N ... =copy_link
I've been selling rough but it has gone fast. I am down to 3-8 gram pieces. We're scrambling to get more--it looks hopeful but nothing is nailed down yet.

As a side note I also just sent Eric a giant ~250g boule top of the classic Ce:YAG which should cut an even bigger stone.

Here is a comparison of some Ce:YAG and Ce:LuAG. Note the uv flashlight is aimed a ways away from the stones.
Image


Didn’t post for a while, how about Gagg? Another ultra bright and fluorescent material. I wonder how to categorise high, medium and day glow Gagg? How long are we talking about for the phosphorescence for each category? And how well they hold their brightest glow respectively?

I only know yellow brighter white green fluorescence holds longer but not as bright. But quality as high glow?


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 Post subject: Re: LuAG: Availability & Properties
PostPosted: Thu Sep 21, 2023 6:41 am 
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And are such LuAG and Gagg manufactured in US like some other YAG or elsewhere?


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 Post subject: Re: LuAG: Availability & Properties
PostPosted: Thu Sep 21, 2023 12:40 pm 
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GAGG's phosphorescence varies a lot. We tried binning it different ways, with 'dayglow' being material that doesn't habe much phosphorescence and 'high glow' having bright and long lasting phosphorescence (it can be visible in a dark froom hours later). These are a bit informal though because duration and brightness can each vary depending on the formula/contaminants and there is a lot of middle ground.

GAGG is grown in a few factories around the world, including the US though I have not gotten any US material yet.

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 Post subject: Re: LuAG: Availability & Properties
PostPosted: Thu Sep 21, 2023 8:27 pm 
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Stephen Challener wrote:
GAGG's phosphorescence varies a lot. We tried binning it different ways, with 'dayglow' being material that doesn't habe much phosphorescence and 'high glow' having bright and long lasting phosphorescence (it can be visible in a dark froom hours later). These are a bit informal though because duration and brightness can each vary depending on the formula/contaminants and there is a lot of middle ground.

GAGG is grown in a few factories around the world, including the US though I have not gotten any US material yet.


I’ve come across some with bright glow right after exposure, and become dim but still visible 3 min later. Considering getting one to cut. It shouldn’t be day glow as far as I know, but what place or level should I consider this among these materials currently used for gem?

And are you looking to restock high glow as well as extra bright LuAG Stephen?


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 Post subject: Re: LuAG: Availability & Properties
PostPosted: Fri Sep 22, 2023 3:31 am 
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That's what I would call 'mid glow', though I've kind of simplified selling it since having too many divisions started confusing some buyers.
I will be restocking some, I need to do a bunch of restocking the next couple of weeks.

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