Most loose diamonds, although appearing colourless, actually have slight tones of yellow or brown. As these tones become more easily apparent, the rarity and the value decrease.
When looking at the general appearance of fancy antique engagement ring, make sure that the stone is appealing to your eye and that it is bilaterally symmetrical.
The diamond Exchange has the worlds largest anniversary rings trading hall, which is equipped to accommodate more than 1,000 people at a time.