... ,Lava Stone,Lava Basalt,Large Hole Basalt 1) Grey color with special large holes 2) Customized sizes accepted. Large Hole Basalt ,Lava Basalt ... as per your customized requirements.1, medium hole lava basalt2, large hole lava basaltVolcanic stone is formed when the lava stream ... kinds of shapes and thickness. Volcanic Lava Stone,Lava Basalt,Large Hole Basalt