Not really an ettiquette question, just something I was thinking about and you girls are pretty awesome so I thought I'd ask you

I don't understand why diamonds are considered the only stone for wedding rings. I personally would prefer something that has color. The price of diamonds is rediculously inflated and I've heard of plenty of people paying for diamonds, but not getting real diamonds. Does anyone know why diamonds are considered the only kind of stone you should get for a wedding ring and if you could pick a different kind of stone what would it be?