The Orthorhombic system is the system of which the unit cell is a rectangular-based right prism, the orthorhombic prism. The three axes have different lengths but the three angles are all 90 degrees. The characteristic symmetry element is a 2-fold symmetry axis: A2. It includes three crystal classes.
The orthorhombic system is one of the seven crystal systems, together with:
Imperial topaz belongs to the orthorhombic system. © Parent Géry, Wikipedia DP
Orthorhombic system - 1 Photo