Buy online and ship your Cushion Cut, Si1 diamond ring to a local Ritani jewelry store near you (US only). When you buy from us, you can be guaranteed your diamond was responsibly sourced and certified by either the GIA or AGSL. Once you've selected your perfect stone, choose from a diverse range of engagement ring styles, including 4 prong solitaire and pave halo ring settings. Our superb customer service team and free gemologist service will give any assistance or direction you need during the selection process. We have partnered with local jewelry stores across the US so that you can see your loose diamond or designer jewelry in person and try before you buy.