21. It crystallizes in the orthorhombic system, but only rarely forms distinct crystals. 22. All minerals of the monoclinic, orthorhombic , and triclinic systems are biaxial minerals. 23. Numerous examples are known with cubic, tetragonal, rhombohedral, and orthorhombic symmetries. 24. This was eventually explained as a mixture of two orthorhombic phases in the mineral. 25. The mineral crystallizes in the orthorhombic crystal system. 26. Its ?-isoform crystallizes into an orthorhombic system with the Cmcm space group. 27. The framework of stilbite is pseudo-orthorhombic with the open channels typical of zeolites. 28. The narrower, modern scientific definition for marcasite as orthorhombic iron sulfide dates from 1845. 29. Teallite forms soft silvery grey mica-like plates and crystallizes in the orthorhombic system. 30. The mineral has an orthorhombic crystal form.