This item was given to me by someone who was a ship's doctor, and I have treasured it. It's a treasure from the sea that is rarely found these days! Moreover, it's a large and valuable piece. As it lives in the deep sea, it has been treated as a rare coral since ancient times and has been prized as decorations for the rosaries of noble monks and the inro of samurai. It is a type of coral that lives in the northern deep sea, 300m to 1000m deep, and is a rare find, occasionally caught by bottom trawling. It is known as Deep Sea Pine (Fukamiru) and Rainbow Coral (Black Coral, Blue Coral). It has a unique luster that no gemstone can match when polished (gold, green, blue), and it is certified as a gemstone. It is a raw material that can be used for various things, such as high-grade seals, accessories, and ornaments.