8 Key Terms Flashcards
Adamantine luster
The highest degree of luster possible in a transparent material.
Angle of incidence
The angle at which a ray of light strikes a surface, measured from the normal.
Angle of reflection
The angle between the normal and a reflected ray of light.
Brightness
The effect of all the diamond’s internal and external reflections of white light.
Critical angle
Angle between the normal and the maximum angle of refraction, which is the largest angle at which rays inside the diamond can escape.
Dispersion
An optical property that’s the difference between the RI values of specific violet and red wavelengths of visible light for a given material.
Fire
The flashes of color you see in a polished diamond.
Luster
The appearance of a material’s surface in reflected light.
Normal
An imaginary line perpendicular to the point where a ray of light strikes the surface.
Pattern
The relative size, arrangement, and contrast of bright and dark areas that result from a diamond’s internal and external reflections.
Polish
The overall condition of the facet surfaces of a finished diamond.
Proportions
The angles and relative measurements of a polished gem and the relationships between them.
Reflection
The bouncing back of light when it strikes a surface.
Refraction
Change in speed and possible change in direction of light as it travels from one material to another.
Refractive index (RI)
A measure of the change in the speed and angle of light as it passes from one material to another.
