Lava Rock Aquarium Safe Natural Lava Rock 3+ Pieces. Natural Lava Rock. Three or more pieces. (2 Large + 2 smaller pieces/order) Total weight Approx. 7.5#'s Excellent in almost any aquarium setting, however be aware may have sharp edges. Natural Rock! Also for use in Gardens, Bonsai, Landscaping...Wherever you choose! All orders shipped Priority Mail. Delivery to Continental USA should be within 5 business days from placing your order.