A uniaxial crystal has one such line, a biaxial crystal has two.
Note: In uniaxial crystals, the optic axis has the direction of the vertical crystallographic axis.
When a uniaxial crystal is examined in a polariscope or polarizing microscope between crossed nicols (i.
Optically uniaxial crystals--corresponding with the tetragonal and hexagonal systems.
Section of the Ray-Surface of a Negative Uniaxial Crystal.
In uniaxial (tetragonal and hexagonal) crystals it is only for light transmitted in the direction of the optic axis that there is rotatory action, but in isotropic (cubic) crystals all directions are the same in this respect.
The isothermal surface in a uniaxial crystal is therefore a spheroid; in cubic crystals it is a sphere; and in biaxial crystals an ellipsoid, the three axes of which coincide, in orthorhombic crystals, with the crystallographic axes.
In uniaxial crystals there are two principal coefficients of expansion; the one measured in the direction of the principal axis may be either greater or less than that measured in directions perpendicular to this axis.
Uniaxial (tetragonal and hexagonal) crystals when showing perceptible differences in colour for the ordinary and extraordinary rays are said to be "dichroic.
In convergent light, between crossed nicols, a very different phenomenon is to be observed when a uniaxial crystal, or section of such a crystal, is placed with its optic axis coincident with the axis of the microscope.
Section of the Ray-Surface of a Positive Uniaxial Crystal.
The optical characters of uniaxial crystals are symmetrical not only with respect to the full number of planes and axes of symmetry of tetragonal and hexagonal crystals, but also with respect to all vertical planes, i.
These two directions are called the optic axes ("primary optic axis"), though they have not all the properties which are associated with the optic axis of a uniaxial crystal.
The surface expressing the magnetic character in different directions is in uniaxial crystals a spheroid; in cubic crystals it is a sphere.
The isopolar uniaxialor phacotypic ground-form is characterised by the possession of a vertical main axis with {xv}equal poles, whilst no transverse axes are differentiated.
The allopolar uniaxial or conotypic ground-form is characterised by the possession of a vertical main axis whose two poles are unlike, while no transverse axes are differentiated.
Elementary application of double refraction and the polarization which accompanies it inuniaxial crystals when the face of the crystal is parallel to the axis, and the plane of incidence normal or parallel to this axis.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "uniaxial" in a variety of sentences. We hope that you will now be able to make sentences using this word.
