As I began my career in jewelry in 1987, the term cushion cut was known only as a reference to old world (circa 18th century) diamonds. I first encountered them in freshly cut inventories in the late 1990's. Why the sudden shift to a forgotten style? Diamond cutting centers were responding to the retro look trend in bridal jewelry styles. Very soon the designers began sketching this shape into the center of their new retro styles, printing them in magazine adds, and just like that, a shape was reborn.
Pros and cons? They are an accurate replica of diamonds that were used in 18th century jewelry. They cost less than modern round diamonds of equal weight and quality. Unfortunately the "price" of this savings compared to rounds is that they appear smaller than equal size rounds, and in the comparison of brilliance (a combination of reflected and refracted light) the modern round wins hands down.
So in summary, there was a very good reason the old world cushion cut fell out of use, technological advances in the cutting process were producing a more beautiful diamond, and beautiful is what diamonds are all about.
