Adularescence and Chatoyancy

Good morning everyone.
I’m new to the forum and I’m a TechArt student.
As my diploma work, I was thinking of developing a photorealistic material for gems and crystals and I am having great difficulty with the Chatoyancy effect for the “Tiger’s eye” and “Star Sapphire/Ruby” stones and the Adularescence effect for the “Labradorite” (Schiller effect) and “Moonstone/Adularia” (even just one of the two is sufficient).
Does anyone know of ways to achieve this effect with a material? Possibly I can also use BluPrints and coding, but for the school course, materials would be better.
I’ve searched various forums and sites but haven’t found anything relevant.
If you had anything to recommend to me, articles, sites, guides, manuals, … I would be immensely grateful, no matter the language.
I would like to be able to complete this course with a project with great visual impact and with a good evaluation.
The shader could also be developed on CryEngine (I didn’t find the tag) but it would be better on Unreal, the main school software.
I have consulted several Unreal and Marketplace forums, but it is such a particular thing that no one has ever worked on.
Thank you very much for your attention.

In pre rendered 3d we usually do that by rendering separate meshes (one opaque inside and the outer shell with refraction).

I’ve had quasi similar results on a single object with Renderman RIS, on which you can setup bump for each separated lobes: a base bump for diffuse / specular for the inner part and a separate bump on the coat. What’s still missing is the parallax effect.

So for a real time shader on a single object, I would try to mix a parallax shader acting per lobe.

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Hi, thanks for your kind reply and sorry for the delay.
I’m having trouble testing your solution.
I have no experience with Renderman and am having trouble creating a parallax shader that works for each lobe.
I will soon ask my teacher to see how to do it but if you have more precise instructions I would be very grateful.

I don’t know enough about UE shaders to help you, sorry.

If you can, you should try it out with several meshes inside each other, it might be simpler.