Pls help ID unique stone band

Hi, first time poster here. My mom just gave me my grandfather’s watch. It’s a Seamaster from the 1960s. But I can’t figure out the stone band. Was it a custom band? It has been in storage for decades and has not been serviced. How much is this worth without being serviced?

(I have a vintage Rolex from grandma and a Longines— both not working! This can always be added to the collection… But just curious.
Thanks!