Buying jewelry online

The wife wants diamonds though she knows of my ethical concerns of buying them. That said, I was looking to buy her a nice amethyst ring (she loves purple). My experiences with local jewelers have rarely been pleasant so I was looking to buy online. The ring that has caught my eye specifically is this one: Large Heart Amethyst Ring.
If you are a woman who wanted diamonds, would you like something like this, or be disappointed (it does have a TINY amount of diamond in it)? In addition, have you had any experiences buying jewelry online that might scare me away from purchasing from this site? I do shop online regularly with no problems to date, but this would be a hell of a way to start.
Any feedback would be most appreciated.