Lab14 Biaxial Interference Figures F12 Download Free Pdf Biaxial interference figures in mineralogy this document discusses how to determine the optic sign and estimate the 2v angle of biaxial minerals using optical mineralogy. There are three methods for determining the optic sign of a biaxial mineral using an interference figure: biaxial (bxa) figure, centered optic axis (oa) figure, and off centered bxa or oa figure.
Optical Mineralogy Lab 14 Fall 2012 Biaxial Interference We can get interference figures from all grains, but interpreting them can be difficult or impossible. with care, however, we can identify three different kinds of useful figures: optic axis figures (oa), acute bisectrix figures (bxa), and optic normal figures (on). The acute bisectrix (bxa) figure results when the bxa is perpendicular to the microscope stage. if the 2v angle is < 60°, both melatopes (m), marking the point of emergence of the optic axes, lie within the fov. To determine whether an anisotropic mineral is uniaxial or biaxial, and whether it is optically positive or negative, requires obtaining an interference figure. measuring 2v, for biaxial minerals, also requires an interference figure. Lab 14 – fall, 2012 biaxial interference figures. optical mineralogy. biaxial sign: b x a figures. to determine the optic sign of a biaxial mineral from a bx a figure, position the isogyres so that the melatopes are in the ne and sw quadrants.
Optical Mineralogy Lab 14 Fall 2012 Biaxial Interference To determine whether an anisotropic mineral is uniaxial or biaxial, and whether it is optically positive or negative, requires obtaining an interference figure. measuring 2v, for biaxial minerals, also requires an interference figure. Lab 14 – fall, 2012 biaxial interference figures. optical mineralogy. biaxial sign: b x a figures. to determine the optic sign of a biaxial mineral from a bx a figure, position the isogyres so that the melatopes are in the ne and sw quadrants. ÿÀ ÈÈ " ÿÄ ÿĵ } !1a qa "q 2 ‘¡ #b±Á rÑð$3br‚ %&'()*456789:cdefghijstuvwxyzcdefghijstuvwxyzƒ„…†‡ˆ‰Š’“”•–—˜™š. Explore biaxial mineral optics with this lab manual. learn birefringence, interference figures, optic sign determination, and more. Biaxial interference figures are most useful for the determination of optic sign and estimation of the 2v angle, both of which are useful diagnostic properties of biaxial minerals. • interference figures for biaxial minerals are more varied than those of uniaxial minerals and can be difficult to interpret. however, if a careful choice of mineral grain is made (on the basis of retardation), interpretation is straightforward.
Optical Mineralogy Lab 14 Fall 2012 Biaxial Interference ÿÀ ÈÈ " ÿÄ ÿĵ } !1a qa "q 2 ‘¡ #b±Á rÑð$3br‚ %&'()*456789:cdefghijstuvwxyzcdefghijstuvwxyzƒ„…†‡ˆ‰Š’“”•–—˜™š. Explore biaxial mineral optics with this lab manual. learn birefringence, interference figures, optic sign determination, and more. Biaxial interference figures are most useful for the determination of optic sign and estimation of the 2v angle, both of which are useful diagnostic properties of biaxial minerals. • interference figures for biaxial minerals are more varied than those of uniaxial minerals and can be difficult to interpret. however, if a careful choice of mineral grain is made (on the basis of retardation), interpretation is straightforward.
Optical Mineralogy Lab 14 Fall 2012 Biaxial Interference Biaxial interference figures are most useful for the determination of optic sign and estimation of the 2v angle, both of which are useful diagnostic properties of biaxial minerals. • interference figures for biaxial minerals are more varied than those of uniaxial minerals and can be difficult to interpret. however, if a careful choice of mineral grain is made (on the basis of retardation), interpretation is straightforward.
Comments are closed.