... special large holes 2) Customized sizes accepted. Large Hole Basalt ,Lava Basalt, Lava Stone, Grey basalt, Volcanic stone,Size 30x30, 30x60, 40x60 ... customized requirements.1, medium hole lava basalt2, large hole lava basaltVolcanic stone is formed when the lava stream flows and cools down with ... hammered, etc., with all kinds of shapes and thickness. Volcanic Lava Stone Lava Basalt Large Hole Basalt