Wow, I am overwhelmed by all your comments. Thank you!
I remembered I had this small slab of Labradorite when I was looking for a different background to shoot the diamond on. I was surprised myself about the many different effects I got out of this amazing mineral, just by changing the light and the angle of view. Then I discovered the effect of colors being reflected by the diamond's facets and I went looking for colorful things that would cast their colors to be reflected. All of this with a 100mm macro lens mounted to a 24MP camera, so I would get a decent image size for this small stone.
If I get new ideas on composition, I'll shoot more, while the diamond is not yet set. Oh, and once it is set, the circle starts again from zero.
Again, thank you all for your kind words. It is appreciated. You can tell that it was fun for me to do, and what you are seeing are the six I selected from maybe 30, about two hours worth of work. No, make that two hours worth of fun.
Kenny, I used a Minolta 100mm macro on a Sony 24MP DSLR (A850) on a Gitzo tripod with RRS ballhead. None of that is really that important, it is the person behind the camera that creates the shot . Light came from my halogen desk lamp and a small flash light in all possible and impossible positions and combinations, whatever produced the best results. As I said, I used a small slab of Labradorite as background on my desk and played with angles. This mineral is amazing by itself in how it changes appearance with different lighting and viewing angles. To be honest, it is more striking than the diamond (and costs a lot less)
I also have a rough piece of Lapislazuli and thought it might be a good background as well, but it pales in comparison with the Labradorite.
As I am editing this, I just got the idea to play with a polarizing filter and see what that can add. We'll see.
Second edit. I just counted. Yeah, right. Thirty. They were 78 shots. Still a good yield, six out of 78.
RSS ball head?
Hmm, maybe I should look into those.
I have a Gizto series 3 with the cheapest Gitzo ball head, which is not quick release.
The ball is very very stiff even after adjusting it to be as loose as possible.
Don't necessarily get the RRS. It is just what I have. I think there are better ones. There must be better ones. I just don't know which.
I had a bigger Gitzo ball before, but that was simply too big and heavy for my needs. Smooth, though. My RRS, the 40, is either too loose or too tight. Can't find a cold-honey setting.
So I saw that you are quite the rock shooter yourself. What configuration are you using?