Ass #7- Key Terms and Concepts

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the critical angle of diamond?

24.5 degrees (correct)

20 degrees

45 degrees

30 degrees

How is dispersion in materials measured?

By the temperature of the material

By the color intensity of the material

By the RI difference between red and violet light rays (correct)

By the size of the material

What does a diamond's brightness relate to?

The composition of the diamond

The clarity of the diamond

The diamond's weight

The amount of light reflected back to the observer (correct)

What phenomenon do diamond professionals refer to as 'fire'?

The display of dispersion in the diamond (D) Signup and view all the answers

How can cutting affect a diamond's color appearance?

By altering the length of the path of light in the diamond (D) Signup and view all the answers

What does the GIA Cut Grading System evaluate?

Face-up appearance, design, and craftsmanship (D) Signup and view all the answers

Which type of lighting is most effective for evaluating a diamond's pattern?

Diffused fluorescent lighting (B) Signup and view all the answers

What effect does increased absorption have on colored diamonds?

It results in deeper color (A) Signup and view all the answers

Which factor does NOT influence a diamond's appearance?

The diamond's origin (D) Signup and view all the answers

What is associated with a diamond's small critical angle?

Limits the amount of light that enters (A) Signup and view all the answers

What does the term 'adamantine' refer to regarding a material?

The highest degree of luster possible in a transparent material. (B) Signup and view all the answers

Which statement about the angle of incidence is correct?

It is always equal to the angle of reflection. (D) Signup and view all the answers

What does 'optical density' indicate about a material?

It measures the material's ability to slow down light. (A) Signup and view all the answers

What occurs at the critical angle during light transmission?

Total internal reflection begins to occur. (D) Signup and view all the answers

How does light behave when it travels from a less refractive material to a more refractive material?

It bends toward the normal. (A) Signup and view all the answers

What is 'dispersion' in the context of light?

The separation of white light into its spectral colors. (D) Signup and view all the answers

What does the term 'symmetry' refer to in gemology?

The exactness of a gem's shape and facet placement. (C) Signup and view all the answers

What is indicated by the fact that the refractive index (RI) of air is assumed to be 1?

All gem materials must have an RI higher than 1. (A) Signup and view all the answers

What does the term 'path length' refer to in relation to a light ray?

The total distance a light ray travels within a gemstone. (B) Signup and view all the answers

How does the refractive index affect the critical angle of materials?

Higher RIs lead to smaller critical angles. (C) Signup and view all the answers

What does a small critical angle in diamond primarily limit?

The opportunity for light to exit the stone (B) Signup and view all the answers

What is characteristic of the display of dispersion in diamonds, known as 'fire'?

It exhibits a play of colors when properly tilted (A) Signup and view all the answers

Which aspect is NOT a component of the GIA Cut Grading System?

Technological durability (A) Signup and view all the answers

What effect does longer light travel distance in a gemstone typically have?

Causes more absorption (C) Signup and view all the answers

In what situation is diffused fluorescent lighting most beneficial?

To evaluate a diamond’s brightness and pattern (D) Signup and view all the answers

Which of the following accurately describes the role of cutting in diamonds?

It can change the light path length (B) Signup and view all the answers

What could cause colored diamonds to appear lighter in color?

Shorter light path within the diamond (C) Signup and view all the answers

What primarily influences a diamond's brightness as perceived by an observer?

The amount of light reflected back (A) Signup and view all the answers

Which of the following can affect the appearance of a diamond significantly?

Variations in lighting and surroundings (B) Signup and view all the answers

What effect does the optical density of a material have on the speed of light traveling through it?

Light travels slower in materials with higher optical density. (D) Signup and view all the answers

Which phenomenon occurs at the critical angle during light transmission?

Total internal reflection begins to occur. (A) Signup and view all the answers

What effect does an increase in the angle of incidence have on the angle of reflection?

The angle of reflection increases. (C) Signup and view all the answers

How does light behave when it transitions from a more refractive material to a less refractive material?

It bends away from the normal. (D) Signup and view all the answers

What does the term 'reflection' specifically refer to in the context of light?

The light returned after hitting a surface or boundary. (C) Signup and view all the answers

Which factor is associated with a lower critical angle in a material?

Higher optical density. (D) Signup and view all the answers

What defines the angle of refraction when light enters a new medium?

The angle at which light bends in relation to the normal. (D) Signup and view all the answers

What does the term 'pattern' refer to when evaluating a gemstone?

The arrangement of bright and dark areas when viewed face-up. (C) Signup and view all the answers

What is the significance of a material’s refractive index (RI) being higher than 1?

It signifies the material can slow down light more than air. (A) Signup and view all the answers

What is indicated by the term 'luster' in a material?

The appearance of the material's surface in reflected light. (B) Signup and view all the answers

The angle at which light returns from a surface or boundary, measured between the normal and the reflected light is ?

Angle of Reflection (B) Signup and view all the answers

The angle at which light hits a surface or boundary, measured between the normal and the incident light is ?

Angle of Incidence (C) Signup and view all the answers

An imaginary line perpendicular to the surface of a boundary is ?

Normal (A) Signup and view all the answers

The overall condition of the facet surfaces of a finished diamond is ?

Polish (A) Signup and view all the answers

The change in speed and possible change in direction of light as it travels from one material to another is ?

Refraction (A) Signup and view all the answers

Each cut grade includes a range of .......

proportion combinations and a variety of appearances (B) Signup and view all the answers

A diamond’s face-up pattern reveals nearly all .....

of the cutter’s fashioning choices. (B) Signup and view all the answers

The GIA Cut Grading System applies to round brilliant diamonds in all....

clarities across the D-to-Z color range. (B) Signup and view all the answers

Study Notes

Key Terms

Adamantine: Highest degree of luster in a transparent material.
Angle of Incidence: Angle at which light hits a surface, measured from the normal.
Angle of Reflection: Angle at which light returns from a surface, measured from the normal.
Angle of Refraction: Angle at which light bends when moving between materials, measured from the normal.
Brightness: Effect of internal and external reflections of white light in a diamond.
Critical Angle: Angle of incidence at which refraction angle is 90 degrees, causing total internal reflection.
Dispersion: White light separating into spectral colors.
Luster: Appearance of a material's surface in reflected light.
Normal: Imaginary line perpendicular to a surface.
Optical Density: Medium's ability to slow down light.
Path Length: Total distance a light ray travels in a gemstone.
Pattern: Relative size, arrangement, and contrast in bright/dark areas of a gemstone.
Polish: Condition of facet surfaces on a finished diamond.
Reflection: Light returned when hitting a surface.
Refraction: Change in speed/direction of light when moving between materials.
Refractive Index: Measure of speed/direction change as light moves between materials.
Symmetry: Exactness of a finished gem's shape and facet placement.
Total Internal Reflection: Complete reflection of light within a material.

Key Concepts

Angle of incidence = Angle of reflection
Refractive Index of air = 1
Gem materials have RI > 1
Light travels slower in higher optical density materials (higher RI).
Refracted light bends towards the normal when moving from a less to more refractive material.
Refracted light bends away from the normal when moving from a more to less refractive material.
Materials with higher RIs have smaller critical angles than materials with lower RIs.
Diamond's critical angle = 24.5 degrees.
Dispersion = Difference in RI between violet and red light.
Dispersion varies by material.
More absorption occurs with greater light path length.
Diamond's brightness is related to reflected light.
Diamond's face-up pattern shows cutter's choices.
Diamond's "fire" is its dispersion display.
Color in diamonds is related to absorption (less absorption = lighter color).
Cutting changes diamond's color appearance.
GIA Cut Grading System evaluates round brilliant diamonds (D-Z color range).
Evaluation based on appearance, design, and craftsmanship.
Lighting and surroundings affect diamond appearance
Spot light evaluates diamond fire, diffused light evaluates brightness.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge on key terms related to optics and gemstones. This quiz covers essential concepts like angle of incidence, critical angle, and dispersion, helping you understand the intricacies of light behavior in various materials. Perfect for students and enthusiasts in the field of optics and gemology.