Hi all, hope it's super sunny where you are! I'm starting a new jewelery design rendering project. Till now I've been focused on modeling and animation, so I need to shed some light on caustics and Gi. Could any of you good Houdini folks recommend good caustics/jewelery rendering tutorials compatible with H16.5, preferably videos? Thank you kindly.

For sure!

For rendering anything realistically PBR will probably be your best bet for realistic lighting, and shading.
I'd recommend looking into crystal tutorials, because they seem the best way to good for jem stones, and semi-precious stones.

Tutorials:

entagma :

https://vimeo.com/205629784 [vimeo.com]

https://vimeo.com/216426352 [vimeo.com]

lesterbanks:

https://lesterbanks.com/2019/05/how-to-generate-fractal-mineral-growth-with-houdini/ [lesterbanks.com]

these ones are the only things i can think of at the top of my head.

hope this helps!