Thanks to the nice comment and idea from @MikesWonderland, I made a new version of the flawed diamond, as every carbon flaw comes with a crack flaw, and also I’ve put the diamond in a more suited environment. This image was completely made with BLENDER 2.91 and CYCLES. The only post effect is a vignette effect.
Screenshot of the new scene
What follow is the original post…
The final render of a very special tutorial about diamonds and flaws using BLENDER 2.91 Cycles and Luxcore 2.5 - Tutorial was a great idea from one of my subscribers about creating flaws in gemstones, tutorial is available on my channel https://youtu.be/6TWuOYV1ZJA
The final image is in 4K, combining one render made with Cycles, material and lighting 320 samples with Optix denoising and another render made with Luxcore. GPU render at 850 samples. The image has some vignette, transparency and DOF effects.
Obviously the image is taking advantages from light tracing caustics and dispersion with Luxcore, but I added fake disperions in Cycles to add to the realism. In this occasion, I liked the render from Cycles better because of how Cycles uses the HDR light (or rather said, absense of light), giving more realism to the diamond. Luxcore does handle the light more realistically, but that ends up with a render with too much light. The combined renders just look like a foto.
render from CYCLES
render from LUXCORE