Black Star Lava Rock is a unique variation of the classic aquascaping stone, Black Lava Rock. Black Star Lava Rock features a uniquely rounded shape that is much smoother than other Lava Rock varieties. This characteristic makes the round aquarium stones great for scaping in tanks that contain livestock with sensitive fins such as Fancy Goldfish, Betta Fish and more. Black Star Lava Rock still sports a porous texture that will support a variety of aquarium plants that are commonly grown on aquarium hardscape. Black Star Lava Rock works great as a base stone with driftwood or alone. We recommend wrapping them with aquatic mosses for additional greenery wherever desired!