Colored Stone Essentials - Assignment 2 with comprehensive
questions and answers 2024/2025
What are hue, tone, and saturation?✔️✔️
Light✔️✔️Light is a form of energy that travels in waves. Light looks white, its actually a
combination of the colors red, orange, yellow, green, blue, and violet (The colors of the rainbow,
also called hues). Each color represents light waves of different energies.
Hue✔️✔️Each of the color components of white light is called a spectral hue. Some hues are
"pure" while others are combinations of hues.
Tone✔️✔️Tone is a color's lightness or darkness. Degree of darkness or lightness of a color.
Saturation✔️✔️Saturation is a color's weakness or strength. Highly saturated colors look vivid and
intense. Greens, blues, and violets with low saturation look grayish, while reds, oranges, and
yellows with low saturation appear brownish. A color's strength or intensity.
When light reaches an object, some of its component colors are absorbed by the object, while
others return to the viewer. This exchange between light and the object it shines on is
called:✔️✔️Selective Absorption
Selective Absorption✔️✔️Process by which a material absorbs some components of visible light
and returns others.
How do a gemstone's structure and chemistry affect its color?✔️✔️Each gem species and variety
contains a unique mix of chemicals, and each gem crystal grows in its own way. A gem's
chemical composition and its crystal structure combine to affect the way it absorbs and returns
light. These natural variations contribute to each gem's unique body color.
A gem's chemical composition and crystal structure affect the way it absorbs and returns
light.✔️✔️
, Bodycolor✔️✔️A gemstone's basic color, determined by its selective absorption of light, which is
affected by its chemical composition and crystal structure.
Color Center✔️✔️A small defect in the atomic structure of a material that can absorb light and
give rise to a color. Adding energy from irradiation or heating can remove the defect and change
the gem's color.
Color Variations✔️✔️Most customers expect to see bodycolor spread evenly throughout a
transparent gem. They might not realize that certain gems display more than one color,
depending on how they absorb and return light, their structure, and which combination of
chemicals they contain.
Color zoning✔️✔️Areas of different color in a gem, caused by variations in growth conditions.
There's a reason for color variations in gems—the course of a mineral's growth is never smooth.
If conditions change during growth—for example, if a gem crystal receives greater or lesser
amounts of color-causing nutrients—it will display bands of slightly different colors. This effect
is called color zoning, and it can spoil or enhance a gem's appearance and salability.
Parti-Colored Gems✔️✔️Gems with two or more distinct color zones.
Bi-Color Gems✔️✔️Gems with only two color zones.
Pleochroism✔️✔️When a gem shows different bodycolors from different directions. From the
greek for "having many colors".
Light Return✔️✔️When light enters a gemstone from the top, most of it should bounce off the
bottom of the stone and then reflect out again through the top. This is called light return.
Windowing✔️✔️For a gem to have good light return, it must be well cut. But sometimes the cutter
sacrifices light return in favor of retaining weight from the rough. When a cutter's effort to get
maximum weight from gem rough limits a stone's ability to return light, the effect is called
windowing
questions and answers 2024/2025
What are hue, tone, and saturation?✔️✔️
Light✔️✔️Light is a form of energy that travels in waves. Light looks white, its actually a
combination of the colors red, orange, yellow, green, blue, and violet (The colors of the rainbow,
also called hues). Each color represents light waves of different energies.
Hue✔️✔️Each of the color components of white light is called a spectral hue. Some hues are
"pure" while others are combinations of hues.
Tone✔️✔️Tone is a color's lightness or darkness. Degree of darkness or lightness of a color.
Saturation✔️✔️Saturation is a color's weakness or strength. Highly saturated colors look vivid and
intense. Greens, blues, and violets with low saturation look grayish, while reds, oranges, and
yellows with low saturation appear brownish. A color's strength or intensity.
When light reaches an object, some of its component colors are absorbed by the object, while
others return to the viewer. This exchange between light and the object it shines on is
called:✔️✔️Selective Absorption
Selective Absorption✔️✔️Process by which a material absorbs some components of visible light
and returns others.
How do a gemstone's structure and chemistry affect its color?✔️✔️Each gem species and variety
contains a unique mix of chemicals, and each gem crystal grows in its own way. A gem's
chemical composition and its crystal structure combine to affect the way it absorbs and returns
light. These natural variations contribute to each gem's unique body color.
A gem's chemical composition and crystal structure affect the way it absorbs and returns
light.✔️✔️
, Bodycolor✔️✔️A gemstone's basic color, determined by its selective absorption of light, which is
affected by its chemical composition and crystal structure.
Color Center✔️✔️A small defect in the atomic structure of a material that can absorb light and
give rise to a color. Adding energy from irradiation or heating can remove the defect and change
the gem's color.
Color Variations✔️✔️Most customers expect to see bodycolor spread evenly throughout a
transparent gem. They might not realize that certain gems display more than one color,
depending on how they absorb and return light, their structure, and which combination of
chemicals they contain.
Color zoning✔️✔️Areas of different color in a gem, caused by variations in growth conditions.
There's a reason for color variations in gems—the course of a mineral's growth is never smooth.
If conditions change during growth—for example, if a gem crystal receives greater or lesser
amounts of color-causing nutrients—it will display bands of slightly different colors. This effect
is called color zoning, and it can spoil or enhance a gem's appearance and salability.
Parti-Colored Gems✔️✔️Gems with two or more distinct color zones.
Bi-Color Gems✔️✔️Gems with only two color zones.
Pleochroism✔️✔️When a gem shows different bodycolors from different directions. From the
greek for "having many colors".
Light Return✔️✔️When light enters a gemstone from the top, most of it should bounce off the
bottom of the stone and then reflect out again through the top. This is called light return.
Windowing✔️✔️For a gem to have good light return, it must be well cut. But sometimes the cutter
sacrifices light return in favor of retaining weight from the rough. When a cutter's effort to get
maximum weight from gem rough limits a stone's ability to return light, the effect is called
windowing
