Rating the quality of gem stone, pearl, etc.?
As i know there are different kinds of pearl - man-made, cultured, South Sea, rice pearl, half moon pearl, fresh water, etc.? What's the difference among them? In terms of high grade, can you please rank them accordingly from the highest to the lowest.
Re- jade/coral - what color is considered of great value? for jade - is it the transparent green, mint shaded green, etc. for coral - the very red or slight red orange? Rank accordingly.