The hexactinellid skeleton is constructed of spicules composed entirely of silicates. These spicules are often arranged into a fused network that gives the appearance of a woven, basket-like structure. It is this mesh-like form that gives hexactinellids the firmness and strength required to live at depths of 25 to 8,500 meters (80–29,000 feet). Tissue-like material also containing silicates overlays the spicule structure forming thin fibers that cling to the framework.