SUG 2024 Optical Mineralogy

What are the two main theories explaining the nature of light?

• Reflection and Refraction Theories

• Particle and Wave Theories

• Emission and Absorption Theories

• Scattering and Dispersion Theories

What is the maximum velocity of light in a vacuum?

• 3 x 10^8 cm/sec

• 3 x 10^9 cm/sec

• 3 x 10^10 cm/sec

• 3 x 10^11 cm/sec

Which phenomenon occurs when the retardation between two waves is equal to an integral number of wavelengths?

• Destructive Interference

• Constructive Interference

• Partial Interference

• Refraction

Which of the following is NOT a characteristic of isotropic materials?

• Same velocity in all directions

• Include isometric minerals

• Different velocity in different directions

• Uniform chemical bonds

What is the Index of Refraction (n) a measure of?

• The wavelength of light

• The frequency of light

• The bending effectiveness of light

• The speed of light in a vacuum

What happens at the critical angle when light passes from a medium with a higher refractive index to one with a lower refractive index?

• Light continues in a straight path.

• Light is totally internally reflected.

• Light speeds up and exits at a different angle.

• Light is absorbed by the material.

Which vector of electromagnetic radiation is particularly significant for mineral optics?

• Magnetic Vector

• Electric Vector

• Velocity Vector

• Direction Vector

Who invented the polarizing film in 1928?

• Henri Hureau de Sénarmont

• Edwin Land

• Isaac Newton

• David Brewster

What is the main characteristic of plane polarization (linear polarization)?

• Electric vector vibrates in all directions

• Electric vector vibrates in a single plane

• Forms a helical pattern

• Forms an elliptical helix

Which method of polarization is responsible for the blue sky and colorful sunsets?

• Selective Absorption

• Double Refraction

• Reflection

• Scattering