Not just American, it's pervasive in Europe as well. France is a little unusual in that engagement rings are commonly made from non-diamond gem stones such as rubies, emeralds and sapphires.
Weddings are becoming insane in the UK. I went to a friend's wedding a while back where they had a carved piece of glass showing the seating plan for the dinner. Cost hundreds. They divorced a couple of years later.
The cynic in me would like to see a graph of cost of wedding as a percent of total annual income compared to divorce rates. I have a theory those two things are correlated.
