It’s still rough, and the render isn’t the best (the noise is not PP):
http://mywebpage.netscape.com/ottoana/RGB6.jpg
C&C’s are welcome and so are tips and questions.
Wow. Fantastic. Looks very realistic. Very good lighting. Cool material. I think the time is coming where I also will install yafray on my computer. Right now it doesn’t work, because my computer is so old and my g+±Compiler doesn’t eat the yafray-code. But great result! 
Cute,
are you sure you used the correct IORs? The ‘colored shadows’ looks weird like if the IOR were very close to 1
Stefano
This is not caustic - unfourtantly I didn’t masterd caustic yet 
- the colored shadows are mostly a reflection of the jewel on the plane.
Almost photographic in quality. Very nice design and color selection too, @ner My Yafray attempts have mostly failed. It takes a lot getting used to I guess. I wonder how Blender’s built in ray tracer would render this.
RobertT