Hyuga Suwabute Clamshell, Snow Grade, Size 31, Nachiguro Slate Black Stones included

The traditional craftsmen made Go stones from Suwabute clamshells, a unique species of clam can be only collected on Okuragahama Beach in Hyuga City, Miyazaki prefecture.
 
After years of growth, Hyuga clamshells feature its exceptional thickness, and refined striped pattern compare to the other shells. However, Suwabute clamshell is extinct due to depletion, which makes the existing Hyuga Clamshell Go Stones extremely rare and valuable. And that is why they are also called "The Dreamlike Go stones."
 
Regarding the black stones, namely Nachiguro, are made in Kumano city of Mie prefecture.
 
Snow Grade is the highest quality go stone with fine white stripes that are peculiar to Suwabute clamsshells.