What is a scalenohedron in mineralogy ?
Scalenohedron : definition
A scalenohedron is a closed polyhedron composed of 8 or 12 faces in the form of a scalene triangle (3 sides of unequal lengths), assembled in symmetrical pairs. A distinction is made between the tetragonal or orthorhombic scalenohedron, with 2 pairs of upper faces and 2 pairs of lower faces, and the hexagonal or ditrigonal scalenohedron, with 3 pairs in each hemisphere.
Photo : calcite scalenohedron from Fengjiashan Mine, Daye Co., Huangshi, Hubei, China
Photo : calcite scalenohedron from Fengjiashan Mine, Daye Co., Huangshi, Hubei, China