Any ring can do. It's the thought that counts. Any girl who doesn't like a ring that her man spent time picking out (given that it's not a bubble gum machine ring), then she should appreciate it. If she's like "I wanted 3 carats set in platinum" RUN! She's materialistic!

Having a diamond is the usual tradition. I think that if it comes out of love, then any ring will do.

what the hell an engament ring must atleast have a diamond