I'm very much the same, nelie. I am really, really into semi-precious gemstones, but when it comes to the very expensive stuff, the moral / ethical considerations of contributing to an artificially-controlled demand for stones with very bloody histories just tips the scale. And just for me, personally, I never have understood or wanted to buy into the culturally-constructed mythos around diamonds. In my mind, there are so many other beautiful gems! I just don't get it. Give me moonstone or labradorite over a diamond any day.

In my case, I went with a lab-created alexandrite (still expensive, but not astronomical like increasingly rare mined alexandrite.) Talk about awesome. Really love the color-changing effect (from turquoise to purple, depending on the light.)

Went a little off-topic, but pixie -- you might try looking at Etsy, especially if you'd like something pretty and more reasonable for now while you wait to invest in a smaller size.

http://www.russianbrilliants.net/ has really nice simulated diamonds.

I bought some really nice inexpensive rings off of amazon.com. They tend to be sterling silver which I love. A quick search brought up many choices under $50 that would work as an engagement ring, and they have great tungsten wedding bands too.

Have you ever heard of meteorite rings? It's literally a stone made from a 4 billion year old meteorite. My sister-in-law has one and it looks just like a diamond. It's very sparkly and pretty. When my family and I first saw her ring we said to my brother "holy cow! How could you afford it?" Then later he told us what it was, which I thought was way more interesting and special than a diamond. How many people have meteorites after all?

Good luck. I hope you find the perfect ring.