Thanks to all the reactions, I decided to make smoke and particles directly in BLENDER 2.91 alpha and render with Luxcore 2.4 and then make a new composition.
New version with 3D smoke and particules with BLENDER
Every particle became a light source, so the render at 4K took about 4 hours 30 mins, and I stopped it at 420 samples. Then it is composed to another version with more greenery and different light setup at 1200 samples.
Screenshot of the smoke setup
Designed for an advanced jewelry tutorial with BLENDER 2.9 - rendered with LUXCORE 2.4
Post effects painted in Painter. Scene has been mostly sculpted.
version 1 4K Image - handpainted smoke and sparkles
Some views of the scene