Final answer:
The statement regarding birefringence demonstrable with polarizing microscopy is true. Birefringent materials such as calcite split light into two rays, which can be observed with enhanced contrast using a polarizing microscope, highlighting their optical activity and variations in refractive indices.
Step-by-step explanation:
The statement 'Birefringent; may be demonstrated with polarizing microscopy' is true. Birefringent materials have the unique property of splitting an unpolarized beam of light into two beams with two different values of index of refraction. This phenomenon is known as birefringence.
When such materials are placed in a polarizing microscope, light is polarized and sent through the sample. Upon passing through a birefringent sample, the polarized light is split into two paths with different polarization states: the ordinary ray, which behaves as expected, and the extraordinary ray, which does not comply with Snell's law. As a result, these materials can be analyzed for their unique optical properties, and this effect helps to enhance the visibility of details within the sample, demonstrating birefringence.
Furthermore, polarizing microscopy is invaluable in enhancing the contrast of images, especially for optically active or birefringent materials, by utilizing the differences in how the object affects the plane of polarization. This microscopy technique allows for the detection of variations within the sample, thereby making nearly transparent objects appear with strong color and high contrast, thanks to their birefringent nature.