petrographic microscope in a sentence

Examples

1. Recognising a crenulation in a rock may require inspecting the rock with a hand-lens or petrographic microscope in thin section.
2. Most commonly, rock and mineral samples are prepared as thin sections or grain mounts for study in the laboratory with a petrographic microscope.
3. To observe the interference figure, true petrographic microscopes usually include an accessory called a Bertrand lens, which focuses and enlarges the figure.
4. Under the petrographic microscope, a thin section of the mineral will display brilliant interference figures in greens or blues ( Moore, 1971 ).
5. Petrographic microscopes are constructed with optical parts that do not add unwanted polarizing effects due to strained glass, or polarization by reflection in prisms and mirrors.
6. Addition of plates between the polarizers of a petrographic microscope makes easier the optical identification of minerals in thin sections of optical indicatrices within the visible crystal sections.
7. The two Nicol prisms ( occasionally referred to as " nichols " ) of the petrographic microscope have their polarizing planes oriented perpendicular to one another.
8. The 2H polytype is pleochroic, meaning that the mineral changes colors ( in this case yellow and light yellow ) when viewed at different angles under a polarizing petrographic microscope.
9. In addition to modifications of the microscope's optical system, petrographic microscopes allow for the insertion of specially-cut oriented filters of biaxial minerals ( the quartz wedge, order when needed.
10. Its color in plane-polarized light is dark red, and it does not exhibit pleochroism, which means it does not appear to be a different color when observed at different angles under a polarizing petrographic microscope.