This is obsidian from Oketo, Hokkaido. I believe pieces exceeding 3 kilograms are rare. Compared to obsidian from other locations, this has high transparency, luster, and is homogeneous, making it very beautiful. Due to its unique shape, it might also look good as a base stone for reptiles or other creatures. How about it for making stone tools, science projects, or as a gift? You can easily break it using a household hammer or mallet. Thank you for looking.