Читать книгу Earth Materials - John O'Brien - Страница 112

Tetragonal crystals can possess closed and/or open forms. Common closed crystal forms in the tetragonal crystal system include different eight‐sided dipyramids. Common open forms include four‐sided and eight‐sided prisms and pyramids, as well as pinacoids and pedions. Typical crystal forms and associated minerals in the tetragonal crystal system are shown in Figure 4.25 and Table 4.7.