Podcast
Questions and Answers
What is the term for the pattern of dark vertical lines or bands shown by certain gems when viewed through a spectroscope?
What is the term for the pattern of dark vertical lines or bands shown by certain gems when viewed through a spectroscope?
What is the process where two transition elements with different valences exchange electrons to selectively absorb light?
What is the process where two transition elements with different valences exchange electrons to selectively absorb light?
What is the term for the cloudy bluish white light in a moonstone, caused by scattering of light?
What is the term for the cloudy bluish white light in a moonstone, caused by scattering of light?
What is the term for the crossing of chatoyant bands, creating a star in the dome of a cabochon?
What is the term for the crossing of chatoyant bands, creating a star in the dome of a cabochon?
Signup and view all the answers
What is the term for the movement of electrons back and forth between ions, causing the selective absorption of light?
What is the term for the movement of electrons back and forth between ions, causing the selective absorption of light?
Signup and view all the answers
What is the term for the glittery effect caused by light reflecting from small, flat inclusions within a gemstone?
What is the term for the glittery effect caused by light reflecting from small, flat inclusions within a gemstone?
Signup and view all the answers
What is the term for the direction of single refraction in a doubly refractive gem?
What is the term for the direction of single refraction in a doubly refractive gem?
Signup and view all the answers
What is the term for the two-toned effect seen when a chatoyant gem is positioned at right angles to a light source?
What is the term for the two-toned effect seen when a chatoyant gem is positioned at right angles to a light source?
Signup and view all the answers
What is the term for exposing a gem to man-made radiation to change or improve its color?
What is the term for exposing a gem to man-made radiation to change or improve its color?
Signup and view all the answers
What is the term for the continued emission of visible light after UV or X-ray stimulation stops?
What is the term for the continued emission of visible light after UV or X-ray stimulation stops?
Signup and view all the answers
Which optical phenomenon occurs due to the interaction of visible light with a gem's microscopic internal structure?
Which optical phenomenon occurs due to the interaction of visible light with a gem's microscopic internal structure?
Signup and view all the answers
What is the term for the separation of white light into spectral colors?
What is the term for the separation of white light into spectral colors?
Signup and view all the answers
What is the term for the change in speed and possible change in direction of light as it travels from one material to another?
What is the term for the change in speed and possible change in direction of light as it travels from one material to another?
Signup and view all the answers
What is the term for the appearance of double images of a gemstone's facet junctions on the side opposite the viewer?
What is the term for the appearance of double images of a gemstone's facet junctions on the side opposite the viewer?
Signup and view all the answers
What is the term for the distinct change in gem color under different types of lighting?
What is the term for the distinct change in gem color under different types of lighting?
Signup and view all the answers
What is the term for a small defect in the crystal structure of a material that can absorb light and give rise to a color?
What is the term for a small defect in the crystal structure of a material that can absorb light and give rise to a color?
Signup and view all the answers
What is the term for the process by which a material absorbs some components of visible light and transmits others?
What is the term for the process by which a material absorbs some components of visible light and transmits others?
Signup and view all the answers
What is the term for the emission of visible light by a material when it's stimulated by ultraviolet or X-ray radiation?
What is the term for the emission of visible light by a material when it's stimulated by ultraviolet or X-ray radiation?
Signup and view all the answers
What is the term for a gem colored by trace elements in its crystal structure ?
What is the term for a gem colored by trace elements in its crystal structure ?
Signup and view all the answers
What is the bands of light in certain gems, caused by reflections of light from many parallel needle-like inclusions or hollow tubes?
What is the bands of light in certain gems, caused by reflections of light from many parallel needle-like inclusions or hollow tubes?
Signup and view all the answers
When a gem crystal structure splits light into two rays that each travel at slightly different speed and direction it is called......?
When a gem crystal structure splits light into two rays that each travel at slightly different speed and direction it is called......?
Signup and view all the answers
What is the term for a special kind of interference phenomenon that produces patches of pure spectral color?
What is the term for a special kind of interference phenomenon that produces patches of pure spectral color?
Signup and view all the answers
What is the interaction between two light rays with the same wavelength as they travel along the same path ?
What is the interaction between two light rays with the same wavelength as they travel along the same path ?
Signup and view all the answers
What is a gem colored by an element that is an essential part of its chemical composition?
What is a gem colored by an element that is an essential part of its chemical composition?
Signup and view all the answers
What is an element that can selectively absorb some wavelengths of visible light and produce a color in a gem ?
What is an element that can selectively absorb some wavelengths of visible light and produce a color in a gem ?
Signup and view all the answers
What is a rainbow effect created when light is broken up into spectral hues by thin layers?
What is a rainbow effect created when light is broken up into spectral hues by thin layers?
Signup and view all the answers
A broad flash of color in labradorite feldspar that disappears when the gem is moved is called ...?
A broad flash of color in labradorite feldspar that disappears when the gem is moved is called ...?
Signup and view all the answers
The distance between two adjacent high points of an energy wave is called ...?
The distance between two adjacent high points of an energy wave is called ...?
Signup and view all the answers
When a gem's crystal structure doesn't change incoming light other than by refraction and absorption is referred to as ....?
When a gem's crystal structure doesn't change incoming light other than by refraction and absorption is referred to as ....?
Signup and view all the answers
What term describes a gem showing different
bodycolors from different crystal directions ?
What term describes a gem showing different bodycolors from different crystal directions ?
Signup and view all the answers
What term describes a iridescence sheen in some natural and cultured pearls and mother-of-pearl ?
What term describes a iridescence sheen in some natural and cultured pearls and mother-of-pearl ?
Signup and view all the answers
Study Notes
Optical Properties of Gems
- Absorption spectrum: a pattern of dark vertical lines or bands shown by certain gems when viewed through a spectroscope.
Light Interactions
- Interference: interaction between two light rays with the same wavelengths as they travel along the same path.
- Diffraction: a special kind of interference phenomenon that produces patches of pure spectral colors.
Phenomena in Gems
- Adularescence: the cloudy bluish-white light in a moonstone, caused by scattering of light.
- Iridescence: a rainbow effect created when light is broken up into spectral hues by thin layers.
- Asterism: crossing of chatoyant bands, creating a star in the dome of a cabochon.
- Aventurescence: a glittery effect caused by light reflecting from small, flat inclusions within a gemstone.
Color and Light
- Intervalence charge transfer: a process where two transition elements with different valences exchange electrons to selectively absorb light.
- Allochromatic: a gem colored by trace elements in its crystal structure.
- Charge transfer: the movement of electrons back and forth between ions, causing the selective absorption of light.
Optical Effects
- Chatoyancy: bands of light in certain gems, caused by reflection of light from many parallel, needle-like inclusions or hollow tubes.
- Labradorescence: a broad flash of color in labradorite feldspar that disappears when the gem is moved.
- Milk and honey: a two-toned effect seen when a chatoyant gem is positioned at right angles to a light source.
Gemstone Properties
- Optic axis: direction of single refraction in a doubly refractive gem.
- Orient: iridescence seen in some natural and cultured pearls and mother-of-pearl.
- Color center: a small defect in the crystal structure of a material that can absorb light and give rise to a color.
Luminescence
- Phosphorescence: continued emission of visible light after UV or X-ray stimulation stops.
- Fluorescence: emission of visible light by a material when it's stimulated by ultraviolet or X-ray radiation.
Other Phenomena
- Play-of-color: the flashing rainbow colors in opal, produced by the interaction of visible light with the gem's microscopic internal structure of stacked silica spheres.
- Dispersion: the separation of white light into spectral colors.
- Pleochroism: when a gem shows different body colors from different crystal directions.
- Refraction: change in speed and possible change in direction of light as it travels from one material to another.
- Double refraction: when a gem's crystal structure splits light into two rays that each travel at a slightly different speed and direction.
- Selective absorption: process by which a material absorbs some components of visible light and transmits others.
- Doubling: the appearance of double images of a gemstone's facet junctions on the side opposite the viewer.
- Single refraction: when a gem's crystal structure doesn't change incoming light other than by refraction and absorption.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Test your knowledge of colored stones with this quiz on key terms, including absorption spectrum, interference, adularescence, and more! Learn about the properties and characteristics of different gemstones.
