1. Columbite has the same composition and crystal symmetry ( orthorhombic ) as tantalite. 2. The Danish scientist Nicolas Steno ( 1669 ) pioneered experimental investigations of crystal symmetry . 3. However, note that some piezoelectric materials have a crystal symmetry that does not allow pyroelectricity. 4. The crystal symmetry is monoclinic C2 / c, No . 15, Pearson symbol mS48. 5. Its crystal symmetry was first assigned as orthorhombic, then as monoclinic, and finally as triclinic. 6. Those minerals have same chemical composition but different crystal symmetry : orthorhombic for columbite and tetragonal for tapiolite. 7. Those minerals have same chemical composition, but different crystal symmetry orthorhombic for tantalite and tetragonal for tapiolite. 8. Owing to the crystal symmetry , the tetrahedral coordination between these superstructure units is again a key factor. 9. Le Bail analysis provides a more reliable estimate for the intensities of allowed reflections for different crystal symmetries . 10. Wilhelm R�ntgen discovered X-rays in 1895, just as the studies of crystal symmetry were being concluded.
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