| 11. | Stress versus strain data should be obtained in both uniaxial and biaxial forms.
|
| 12. | In an optical spectrum changbaiite is uniaxial positive and it can be biaxial.
|
| 13. | It belongs in the biaxial group, because it is an orthorhombic mineral.
|
| 14. | Earth is not a sphere, but an irregular shape approximating a biaxial ellipsoid.
|
| 15. | The angle between the two axes is denoted by 2V . Vauxite is biaxial.
|
| 16. | All minerals of the monoclinic, orthorhombic, and triclinic systems are biaxial minerals.
|
| 17. | Biaxial minerals are further subdivided by optic sign.
|
| 18. | In sarabauite crystals this angle is obtuse, thus the mineral is biaxial negative.
|
| 19. | Being triclinic, ulexite is optically biaxial.
|
| 20. | Optically, this mineral is biaxial negative, meaning that it contains two optic axes.
|
