Diamonds And Color (Chapter 12, Key Terms & Key Concepts)

Question 1

Annealing—Using heat to stabilize irradiated color in
gemstones.

Answer 1

Annealing

Question 2

Structural defect that influences an
object’s absorption of light and can cause its color.

Answer 2

Color center

Question 3

Yellow, brown, and gray diamonds
with more color than the Z masterstone, or that
exhibit any other color face-up.

Answer 3

Colored diamonds

Question 4

Emission of visible light by a material
when it’s exposed to ultraviolet radiation

Answer 4

Fluorescence

Question 5

Range of diamond colors from
colorless to light yellow, brown, and gray, also called
the D-to-Z range.

Answer 5

Normal color range

Question 6

Process by which a material
absorbs some wavelengths of light and transmits
others.

Answer 6

Selective absorption

Question 7

Many people think of diamonds as colorless, but most diamonds
have a small amount of color, usually yellow or brown.

Answer 7

Key Concept

Question 8

The three elements used to describe color are hue, tone, and
saturation.

Answer 8

Key Concept

Question 9

The presence of impurities and structural defects are two
common causes of color in diamonds

Answer 9

Key Concept

Question 10

Nitrogen is the most common impurity element in diamond
and the most common cause of its yellow color.

Answer 10

Key Concept

Question 11

About 35 percent of gem-quality diamonds fluoresce when
they’re exposed to ultraviolet radiation, and most of them
fluoresce blue.

Answer 11

Key Concept

Question 12

Ethical gem professionals disclose all diamond treatments

Answer 12

Key Concept

Question 13

Colored diamonds are far more rare than diamonds in the
normal color range.

Answer 13

Key Concept

Question 14

With colored diamonds, value depends on the amount of color
they possess

Answer 14

Key Concept

Question 15

Brown is the most common colored diamond color.

Answer 15

Key Concept

Question 16

Increased supply and marketing led to the growing popularity
of colored diamonds.

Answer 16

Key Concept

Question 17

The relative lightness or darkness of a color is called its

Answer 17

tone.

Question 18

The emission of visible light by a material when it’s exposed to ultraviolet radiation is called

Answer 18

fluorescence.

Question 19

The most common colored diamond color is

Answer 19

brown.

Question 20

Which of the following diamond colors would be the most valuable, all other factors being equal?

Answer 20

Red

Question 21

Type IIb diamonds contain

Answer 21

boron.

Question 22

When boron is present in a diamond’s crystal structure, it colors the diamond

Answer 22

blue.

Question 23

A common method of permanently changing the color of a diamond is

Answer 23

irradiating.

Question 24

The basic causes of a diamond’s color are its crystal structure and

Answer 24

chemical composition.

Question 25

Diamonds that are colorless to light yellow, brown, and gray fall into the

Answer 25

normal color range.

Question 26

Type I diamonds contain

Answer 26

nitrogen.

Question 27

When a gem absorbs some wavelengths of light and transmits others, the process is called

Answer 27

color center

Question 28

The most common impurity element found in diamond is

Answer 28

nitrogen.

Question 29

The most commonly observed color of fluorescence in gem diamond is

Answer 29

blue.

Question 30

A structural defect that influences a gem’s absorption of light is called a(n)

Answer 30

selective absorption

Question 31

A noticeable “oily” appearance seen in some diamonds is usually the result of

Answer 31

very strong fluorescence