Engagement Ring?

My boyfriend was thinking about getting me one of these as a engagement ring. I told him that they're beautiful and I'll say yes either way but I want people to know we are engaged just by looking at it and not just thinking it was a gift for my birthday or something. Was I totally wrong to say that? Do you think these are engagement "level"? (This has nothing to do with price and I would say yes with to any ring because it's more about marrying him than having jewelry to me but anyway)

Here are the pics

They really are absolutely gorgeous and I had originally saved the page without his knowledge as something I wanted to get in the future. I just don't know. Thoughts?