Congratulation for the awesome story and that BLOB OF LIGHT!!!
That ring is close to my size, funny to see how huge that 2cts looks on your finger
It may help to use indirect light (i.e. do not direct the lighting source on the stone) and difuse it (white paper pegged infront of the light works). Can you use the macro mode of the camera?
my finger is 4.75 and its great to be able to see the picture of ur ring on ur hand.
for photo-taking, use the macro setting (which is the flower picture on digital cameras), get as close as u can without it being blurry and take a pic, works best with a tripod or on a flat surface. some others have great sucess with using their 10x loupes instead of the macro setting. use photoshop or another similar software to crop the pic to around the ring and voila, a clear close-up shot.