The mineral is brittle, with an uneven splintery fracture. Ganisters are cemented with secondary silica and typically have a characteristic splintery fracture. They are cemented with secondary silica and have a characteristic splintery fracture. Cleavage is perfect, two directions in the shape of a diamond; fracture is uneven, splintery. Other types of fracture are fibrous, splintery, and hackly. It has a Mohs hardness of 3, exhibits no cleavage and has a splintery fracture.