The choice is totally yours. You could make your choice depending on your purpose for buying -- for example, you could buy whichever object you believe will have the greatest value in ten years.
Sure! If the diamond is worth enough.
a aura diamond is a man made diamond.
If it's a mined diamond, the diamond is as old as the earth itself.
No, it is just the style of the chain. There are no actual diamonds in a diamond cut chain.