Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Colored Stones Exam > GIA Colored Stones Exam 451-500 > Flashcards

GIA Colored Stones Exam 451-500 Flashcards

1
Q

Interaction of two light rays traveling the same path.

A

interference

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

A rainbow effect created when light is broken up into spectral hues by thin layers.

A

iridescence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

A broad flash of color in labradorite feldspar that disappears when the gem is moved.

A

labradorescence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

A two_toned effect seen when a chatoyant gem is positioned at right angles to a light source.

A

milk and honey

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Direction of single refraction in a doubly refractive gem.

A

optic axis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Iridescence seen in some natural and cultured pearls and mother_of_pearl.

A

orient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

An unusual optical effect displayed by a gem.

A

phenomenon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The flashing rainbow colors in opal.

A

play_of_color

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

When a gem shows different body_colors from different cystal directions.

A

pleochroism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Change in speed and possible change in direction of light as it travels from one material to another.

A

refraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

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

A

selective absorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

When a gem’s crystal structure doesn’t change incoming light other than by refraction and absorption.

A

single refractive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Elements that can selectively abrorb some wavelengths of visible light and produce color in gems.

A

Transition elements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Which gemstone occurs in almost every color?

A

Tourmaline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

The first impression of an object’s basic color is its ___________ .

A

hue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Generally; cool_colored hues with low saturation look ____________ .

A

grayish

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Use trade terms that imply geographic origin only if the ________________ .

A

gem’s actual source is known

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Which trade term describes certain tourmalines? A. Paraiba B. Kashmir C. Sandawana D. Mozambique

A

A. Paraiba

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the GIA Colored Stone Grading System’s abbreviation for a “slightly purplish red hue” ?

A

slpR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

In practice; what GIA Colored Stone Grading levels apply to grading transparent colored stones?

A

2 through 8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

A see_through area cut in a transparent gemstone’s bodycolor that usually results from the way the gem was cut is called _____________ .

A

a window

22
Q

A window usually differs from the rest of the stone in _______________ .

A

saturation

23
Q

Extinction results from ____________ .

A

deep pavilions

24
Q

The color of the background for grading a colored stone should be ______ .

A

neutral.

25
Q

What type of lighting is best for grading color in a colored stone?

A

daylight_equivalent fluorescent

26
Q

Higher levels of saturation are usually found in stones with ___________ .

A

medium to medium_dark tones.

27
Q

What two coloring agents are usually responsible for color change in gemstones?

A

chromium and iron

28
Q

Emission of visable light by a material when it’s exposed to invisable ultraviolet radiation is called __________ .

A

fluorescence

29
Q

You should judge a gemstone’s beauty and value only by comparing it to what?

A

A sample of its own species or variety.

30
Q

Cutting compromises that save weight can also cause what __________; __________ or ___________ .

A

windows; extinction; both

31
Q

What do you use; in a buying situation; when you cannot control the lighting conditions?

A

comparison stones or color samples

32
Q

A laboratory_created gem with essentially the same chemical composition; crystal structure; and properties as its natural counterpart is called a _____________ .

A

synthetic

33
Q

The two main types of processes for synthetic gem production are melt and ____________ .

A

solution

34
Q

Low cost and high volume characterize which synthetic process?

A

flame fusion

35
Q

What synthetic process developed rapidly due to laser research in the late 1960’s?

A

pulling

36
Q

What process uses a heating unit to pass over a rotating solid rod of chemicals until it forms a synthetic crystal?

A

floating zone

37
Q

What process dissolves nutrients in chemicals to form synthetic crystals?

A

flux growth

38
Q

The crucibles that work best for flux growth are made of what material?

A

platinum

39
Q

The hydrothermal growth process is the only method used to produce which synthetic gem?

A

quartz

40
Q

What synthetic process uses an autoclave?

A

hydrothermal growth

41
Q

Synthetic opal is grown using microscopic silica spheres that are produced by _________ .

A

precipitation

42
Q

What process involves heating finely ground powder; sometimes under pressure; to produce a fine_grained solid material?

A

ceramic

43
Q

Synthetic turquoise is most likely produced by what process?

A

ceramic

44
Q

The flux used in the flux process is a solid material that; when molten it ____________ .

A

disolves other materials

45
Q

The hydrothermal synthetic process requires what?

A

a pressurized steel container and crushed chemical ingredients

46
Q

A snakeskin structural pattern is typical of what synthetic?

A

synthetic opal

47
Q

A process in which powdered chemicals are dropped through a high_temperature flame onto a rotating pedestal to produce a synthetic crystal.

A

flame fusion

48
Q

A melt process where a heating unit passes over a rotating solid rod of chemicals until it forms a synthetic crystal.

A

floating zone

49
Q

A process in which nutrients dissolve in heated chemicals; then cool to form synthetic crystals.

A

flux growth

50
Q

A process in which nutrients disolve in a water solution at high temperature and pressure; then cool to form synthetic crystals.

A

hydrothermal growth

Colored Stones Exam (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions