I am planning on 18k white gold with an yellow gold head. I am pretty sure that is what David and I discussed. I worked a really long day today and am exhausted so my brain is all muddled. LOL!
Mikla, I don't think my photos are so great actually but thank you so much for the compliments. The photos turn out so much better when I have access to more light. I guess one key thing to taking good jewelry photos is having a camera with a MACRO function. I have a Canon SD 870 (or something close to that) and it is a few years old right now but it's a very good camera. Fits in your pocket and takes great photos!
I put the ring or stone on top of an empty jewelry box. I find white to be the best color. Heck, any small box is good and you could even put a small piece of plain white paper on top of it to make it white.

When possible I go outside and put it in the sun but that isn't always available so I find a place inside near a window with a lot of light. Lots of light is important! I turn on the macro function and either hold the camera very steady or prop it up on the table or window ledge. The jewelry box (or lid) holds the stone/ring up just enough to be "eye level" with the camera but sometimes it can take some doing with various objects around the house to get the height of the ring/stone even with the camera.
It helps to not have to hold the camera while taking the photo so you get no movement. Macro is very sensitive to movement. I have gotten pretty good at taking photos without having to set the camera down but when I first started it was the only way to get clear photos. Also, if you have a timer delay on the camera, that can help too since the camera tends to move slightly as you are pushing the button down.
I get as close as I can to the object without it going out of focus and take a TON of photos. I usually try to move and adjust the stone or camera slightly each time so I can look at the photos later and pick the best ones. I use Picasa to edit the photos and crop them as close as possible. I throw out a lot of photos during this process and it can take some time to decide which ones are the best.
Sorry for the long explanation but I hope that helps? Let me know if I need to clarify!