Vintage Antique Very Unusual Ring

I'm pretty sure it is an Orange Sapphire from what I have read on web... possibly a Citron. Idk. From the 1920's or earlier..maybe much earlier.... looks like REALLY old. The small size makes me think it is from when people were smaller My grandmothers or maybe her mothers.. I am a senior. The setting is what I find so unique... I scoured the internet and can't find one like it. It's for a quite small hand. It is stamped Sterling on the inside. Looks like something a Targaryen would wear. or a Queens pinky finger.