It looks like a piece of turquoise, you might see if you can get a clearer picture? The hallmark is giving me trouble. See it as a RS? The closest example is Randall Sahmie but it has him as a Hopi artist and does overlay. However, I wasn’t able to find the work in a quick google search.
Yes it is a rs in a form of a brand it is a set and u am trying to find the rest in my storage it is a large cuff a ring squash blossom earrings and this pendant