I've noticed the first thing people will ask after I tell them I'm engaged is "Let me see the ring!" So I show them and tell them the story of my engagement. The sweetness of the story always wins over the lack of a diamond, but I have always said that it's a 'placeholder' ring. The responses I've received have varied from; "You don't need a fancy ring to feel engaged." to "Let me go diamond shopping with you!"
The more I think about it the more I'm not sure if I want an expensive sparkly thing. I don't know if anything else will feel more like an engagement ring than the one I have now. I change my mind about it every day but right now I think I am content wearing my heart shaped Gion ring. We might spend some time and care picking out and designing our wedding bands and I might want a fancy ring for our anniversary. Or not. What matters to me is the love behind the ring, and that's not going anywhere. Ring or no ring.